User:Hurricaneboy23/2020 Tropical Cyclones

These are the Tropical cyclones of 2020. Yes, the article Tropical cyclones in 2020 exists, but this is just a different way to see the same data of the 142 tropical cyclones that formed that year (excluding the ones which formed in the 2020-21 southern hemisphere seasons for simplicity sake). Lots of record breaking ones as well. Just think of this as all the season articles mushed together into one huge one.

Tropical Cyclone Blake
During 4 January, the BOM reported that Tropical Low 02U had started to develop within a monsoon trough, about 750 km (465 mi) north-northwest of Broome. Citing considerable rotation extending into the mid troposphere, well-established dual-channel outflow and warm sea surface temperatures, the JTWC assessed the system as having a moderate chance of attaining tropical cyclone intensity within the following 24 hours. The system gradually gathered strength in the favourable environment as it tracked slowly towards the south-southwest, leading the JTWC to issue a tropical cyclone formation alert at 03:30 UTC the following day. The BOM indicated that sustained gale-force winds had developed on the western side of the tropical low at 15:00 UTC, and the system was designated as Tropical Cyclone 06S by the JTWC a few hours later. Gales fully encircled the system by 00:00 UTC on 6 January, prompting the BOM to upgrade the low to a Category 1 tropical cyclone on the Australian scale, the first of the season. The system was given the official name Blake by the BOM. Blake began to intensify steadily after being upgraded into a tropical cyclone, attaining 10-minute sustained winds of 75 km/h (45 mph) and one-minute sustained winds of 95 km/h (60 mph) within a few hours. Soon afterwards, however, the system's development stalled due to land interaction with the nearby coastline of Western Australia. The cyclone made landfall on Dampier Peninsula just before 09:00 UTC, approximately 85 km (55 mi) north of Broome. Blake turned to the southwest and re-emerged over the Indian Ocean at 15:00 UTC; however, the system's structure had deteriorated significantly while the centre was over land. As the weakened cyclone continued over water towards the southwest, paralleling the coastline, low vertical wind shear allowed an area of deep convection to gradually redevelop over the system on 7 January. Blake made its final landfall just to the west of the Wallal Downs cattle station on Eighty Mile Beach at approximately 17:00 UTC at minimal Category 1 intensity. Within an hour of crossing the coast, the system weakened to a tropical low. The JTWC discontinued advisories at 00:00 UTC on 8 January as the system moved farther inland; however, the system maintained tropical storm intensity until 12 hours later.

Severe Tropical Cyclone Claudia
On 4 January, the BOM noted the formation of a weak tropical low over Indonesia's Maluku Islands. In the ensuing days, the tropical low tracked slowly southeastwards across the Arafura Sea, towards the Gulf of Carpentaria. Significant development was hampered by strong vertical wind shear; however, very warm sea surface temperatures of up to 32 °C (90 °F) allowed the low to gradually increase in organisation. On 7 January, shortly after the low passed near Cape Wessel in the Northern Territory, the BOM published their first forecast track map for the system, and issued a tropical cyclone watch for the northern coastline of Arnhem Land. On the next day, the JTWC issued a Tropical Cyclone Formation Alert on the system as it began to organize just northwest of the Gove Peninsula. As the system remained disorganized, the JTWC cancelled the first tropical cyclone formation alert, but later issued another one on 10 January as it re-organized itself, following land interaction with the Top End. It was later upgraded to a tropical cyclone by the BOM as it was northeast of Kalumburu, receiving the name Claudia on 11 January. On the next day, the system was upgraded to a category 2 tropical cyclone. Several hours later, following a decrease in wind shear, Claudia's structure quickly improved, with the storm acquiring hurricane-force winds. It was then upgraded by the BOM to a severe tropical cyclone, during this intensification spell.

The storm continued intensifying, indicated by an improvement of the storm's structure over the proceeding hours. The storm eventually reached its peak intensity with 1-minute sustained winds of 90 mph (150 km/h) and 969 millibars with a small, ragged eye forming on microwave imagery on 13 January. Despite this, a decrease in sea surface temperatures as it quickly accelerated eastwards caused the storm to rapidly weaken throughout 14 January, indicated by a loss of deep convection near the storm's center. The next evening on 15 January, the BOM issued their last advisory on Claudia as it began to weaken. Claudia dissipated as a tropical low on 17 January.

When the system was still a tropical low on 10 January, portions of the Top End received unusually large amounts of rainfall due to the system's slow movement. Darwin received 45 mm (1.7 inches) of rain, Noonamah received 56 mm (2.2 inches of rain, Pirlangimpi received 80.8 mm (3.1 inches) of rain, Charles Point received 151 mm (5.9 inches) of rain, and Dum In Mirrie Island received a staggering 410 mm (16.1 inches) of rain as a result of the system.

Tropical Low 04U
On 24 January, the BOM noted that a weak tropical low had formed inland over the northeastern Northern Territory, near Cresswell Downs. Embedded in a low-pressure trough stretching across northern Australia and into the South Pacific Ocean, the tropical low remained slow-moving over the ensuing days. After meandering just south of the Gulf of Carpentaria, the system moved offshore at about 12:00 UTC on 27 January, just to the southeast of Mornington Island. This allowed atmospheric convection to develop, and the central atmospheric pressure deepened to 998 hPa (29.47 inHg) at 18:00 UTC. The system's period over water proved short-lived, however, and the tropical low moved into the Gulf Country of northern Queensland a few hours later. On 29 January, the tropical low began to track rapidly southwestwards towards central Australia, causing the system's convection to degrade due to interaction with the dry Australian outback. The tropical low dissipated near Alice Springs in the southern Northern Territory the following day.

Persisting thunderstorms associated with the low brought long-lived heavy rainfall throughout much of Gulf Country in northern Queensland, due to the storm's abnormally slow movement. The town of Townsville received over 320 mm (12 inches) of rain, breaking the previous daily rainfall record in the town of 190 mm (7 inches). An apartment building was reported to have "severely flooded" near the same town. A peak 475 mm (18.7 inches) rainfall total was recorded at the Ayr DPI Research Station in northern Queensland, as a result of the low.

Severe Tropical Cyclone Damien
As a monsoon trough began to develop over parts of central northern Australia on 2 February 2020, the BOM noted that an inland tropical low had formed over the Northern Territory, within the monsoon trough. On 4 February, it emerged over the eastern Indian Ocean, and the JTWC labelled the system as Invest 92S. A tropical cyclone formation alert was promptly issued early the following day by the JTWC as convection began to steadily develop near the centre. The next day, the JTWC issued its first advisory on the system as a tropical storm. Several hours later, the BOM followed suit, upgrading the storm to a Category 1 tropical cyclone and giving it the name Damien. Damien strengthened into a Category 3 (Australian scale) cyclone and within 48 hours hit western Australia. At that time, it was of equal intensity to a Category 2 hurricane on the Saffir-Simpson scale. On February 9, it dissipated.

In preparation for Damien, the Australian Bureau of Meteorology issued a red alert from Whim Creek to Mardie stretching south to Millstream, and a yellow alert from Port Hedland to Whim Creek extending southwards to Wittenoom. Evacuation centres were set up in Karratha and South Hedland. An urban search and rescue team was also stationed in Port Hedland. Damien brought gale-force winds, torrential rain, and floods to Western Australia when it made landfall near Karratha on 8 February. Wind gusts exceeding 205 km/h (125 mph) were recorded near the landfall point. Over 230 mm of rain fell in Karratha and Roebourne from 8–9 February. The Department of Fire and Emergency Services received more than 100 calls for assistance. Around 9,500 customers in the Pilbara region lost power. Besides downing power lines, strong winds also toppled several trees and caused some buildings to lose their roofs. Karratha Airport was forced to close on the morning of 10 February after the terminal sustained damage and lost power; the airport reopened in the afternoon. It was the strongest tropical cyclone to cross the Western Australia coast since Cyclone Christine in 2013.

Tropical Low Uesi
On 26 January, a low-pressure system formed to the east of the Solomon Islands, centred within a very long low-pressure trough stretching from Western Australia to the central South Pacific Ocean. The low-pressure system tracked generally towards the west over the following days, moving into the Australian region from the South Pacific basin on 27 January. On 3 February, a few days after the low-pressure trough had evolved into a monsoon trough, the BOM noted that the low-pressure system had developed into a tropical low. At the time, the atmospheric environment was assessed as being unfavourable for tropical cyclogenesis; however, the BOM indicated that conditions were likely to become more conducive over the following week. The system moved eastwards onto the boundary of the region—the 160th meridian east—at approximately 06:00 UTC on 4 February, before returning to the Australian region proper later that day. By 06:00 UTC on 5 February, however, the system had moved eastwards out of the Australian region once again. The system later intensified into a tropical cyclone while tracking southwards in the South Pacific basin, and was named Uesi by the Fiji Meteorological Service (FMS). Uesi reached peak intensity as a Category 3 severe tropical cyclone to the northwest of New Caledonia.

After it began to weaken on 12 February, the FMS passed official responsibility for Uesi back to the BOM at 12:00 UTC, despite the system still being located in the South Pacific basin. At this time, Uesi adopted a south-southwestwards track towards the Australian region, and began to experience an increase in northwesterly vertical wind shear. The cyclone's convective structure rapidly deteriorated in the increasingly hostile environment, and Uesi's low-level circulation centre soon became exposed from the central dense overcast. However, despite the decreasing sea surface temperatures and the effects of wind shear and strong upper-level winds, Uesi maintained strong winds in its low-level core. At 00:00 UTC on 13 February, the tropical cyclone commenced extratropical transition while approaching the Australian region, and was downgraded to a storm-force tropical low. Ex-Tropical Cyclone Uesi re-entered the Australian region just before 15:00 UTC with sustained winds of 95 km/h (60 mph) and a central barometric pressure of 979 hPa (28.91 inHg).

The BOM issued a tropical cyclone warning for Australian Tasman Sea territory of Lord Howe Island at 06:00 UTC on 12 February in anticipation of Uesi generating destructive winds while passing nearby. A BOM forecaster noted that the island could conceivably experience winds of up to 155 km/h (96 mph) in association with the system, a fact he described as "quite extraordinary", given that winds of 120 km/h (75 mph) are only observed on the island once every ten years on average. The system made its closest approach to the island at 18:00 UTC on 13 February, passing just 20 km (10 mi) to the southeast as a storm-force extratropical cyclone. A few hours prior, a maximum wind gust of 154 km/h (96 mph) was observed at Windy Point and a gust of 124 km/h (77 mph) was recorded at Lord Howe Island Airport. Minor damage to buildings and vegetation was reported across the island; however, no substantial losses were incurred. As Uesi tracked further south, the BOM cancelled the tropical cyclone warning for the island at 06:00 UTC on 14 February. Uesi generated powerful waves and swells along the coast of southeastern Australia while tracking through the Tasman Sea, with hazardous surf warnings issued by the BOM for beaches along the entire New South Wales coast, as well as for the Gold Coast, Sunshine Coast and Fraser Island in Queensland. On 15 February, a man drowned and a woman was hospitalised with laceration injuries after they were overcome by the dangerous surf conditions at Bondi Beach in Sydney. Uesi exited the Australian region for the final time on 15 February, and tracked towards the South Island of New Zealand.

Tropical Cyclone Esther
A tropical low was reported to have formed by the BOM in the Gulf of Carpentaria on 21 February. The tropical low quickly organized over the pursuing days, showing significant bursts of convection to the north of its centre. The low was eventually upgraded into a Category 1 tropical cyclone, being given the name Esther on 23 February. Moving quickly south, Esther eventually made its first landfall on Mornington Island around 20:30 UTC, where a peak 988 mb pressure reading was recorded. Esther retained its intensity despite the land interaction, and make its second and final landfall near the Northern Territory-Queensland border 6 hours later at 2:00 UTC, 24 February. Weakening below tropical storm intensity quickly after landfall. Esther was declared to have become a Ex-Tropical Cyclone about 2 hours later. Continuing to move further inland under the influence of a subtropical ridge, Esther's remnants shifted in a more westerly direction. Esther's convection and structure however stayed consistent far inland and led to the JTWC noting a low possibility of regeneration as it moved west towards the Eastern Indian Ocean. Over the proceeding days, Esther's remnant low was given a medium chance of re-development over land. As a result of the brown ocean effect, Esther's convection steadily re-developed over land on 27 February as it drew moisture from the nearby water. A tropical cyclone formation alert was then issued for the system's remnants that same day as it was now likely to briefly emerge over the Joseph Bonaparte Gulf. However, by the next day, Esther was deemed not likely to emerge overseas contrary to forecast and the TCFA was cancelled while its convection weakened yet again. On 29 February, the TCFA was re-issued as Esther's center skirted the northeastern Kimberley coast. On 1 March, the TCFA was once again cancelled as the system began moving further inland. As it did so, convection decreased rapidly. The remnants persisted for 4 days, before finally dissipating in the Australian desert.

Rainfall from Ex-Tropical Cyclone Esther caused much welcome rainfall to normally dry areas across the Northern Territory, where some flooding was reported. As much as 258 mm (10.15 inches) of rain fell at the cattle stations Eva Downs Station and 107 mm (4.21 inches) at Anthony Lagoon Station. In preparation for severe thunderstorms associated with the cyclone's remnants, Flood Warnings and Watches were issued across much of the Top End (including Darwin) throughout Esther's passage.

Severe Tropical Cyclone Ferdinand
At around 23:00 UTC on 22 February, the BOM reported that a tropical low had developed within a low-pressure trough over the far-eastern Indian Ocean. Located approximately 285 km (175 mi) south-southwest of Indonesia's Sumba island, the system remained slow-moving initially, before adopting a track towards the southwest on 23 February. The tropical low developed rapidly in a favourable environment for intensification characterised by abundant atmospheric moisture, sea surface temperatures in excess of 30 °C (86 °F), low vertical wind shear and strong outflow in the upper troposphere. The tropical low's convective structure improved considerably during the night, and the JTWC upgraded the system to a tropical storm on the Saffir–Simpson hurricane wind scale (SSHWS) at 18:00 UTC. The BOM followed suit at 00:00 UTC on 24 February, officially upgrading the system to a Category 1 tropical cyclone on the Australian scale and assigning the name Ferdinand.

Ferdinand continued to track slowly southwestwards while gradually intensifying, before turning towards the south at 12:00 UTC. Despite deep convection continuing to develop near the centre of the cyclone throughout the day and into the evening, the system was not able to consistently maintain cold cloud top temperatures. In the diurnally favourable overnight period, however, increased deep convection began to wrap around the centre, and an intermittent eye feature emerged on enhanced infrared satellite imagery. The small size of Ferdinand's wind field allowed the system to strengthen rapidly into a Category 3 severe tropical cyclone on the Australian scale at 00:00 UTC on 25 February. Ferdinand was also upgraded to Category 1 on the SSHWS by the JTWC at this time. The rapid intensification phase continued throughout the day as deep convection bloomed around the system's warming eye and rapidly consolidating eyewall structure. Ferdinand strengthened to Category 2 intensity on the SSHWS just six hours later. The BOM reported that Ferdinand peaked in intensity at around 18:00 UTC as a high-end Category 3 severe tropical cyclone on the Australian scale, with estimated maximum 10-minute sustained winds of 155 km/h (100 mph) and a central barometric pressure of 960 hPa (28.35 inHg). At the time, the JTWC assessed the system as a maximal Category 2 tropical cyclone on the SSHWS, with estimated one-minute sustained winds of 175 km/h (110 mph). Despite being a strong tropical cyclone, no rain or wind impacts were observed in Western Australia due to Ferdinand's highly compact wind field, with sustained gale-force winds extending only 95 km (60 mi) from the circulation centre.

Around this time, Ferdinand's equatorward outflow channel began to be affected by outflow from the approaching Ex–Tropical Cyclone Esther, located approximately 1890 km (1175 mi) to the east, over the Northern Territory. During 26 February, a layer of peripheral dry air in the lower troposphere also started becoming entrained into the system's circulation. The combined effects of these atmospheric changes caused Ferdinand to begin to weaken quickly. The previously well-defined eye became indiscernible on satellite imagery, and deep convection began to reduce in coverage around the system. Ferdinand weakened to Category 1 on the SSHWS at 00:00 UTC the following day, and the BOM downgraded the system to Category 2 on the Australian scale six hours later. Under the steering influence of a mid-level ridge located to the southeast, Ferdinand began tracking towards the west-northwest, and then westwards, on 27 February. After being downgraded to a tropical storm on the SSHWS at 12:00 UTC, Ferdinand's rate of weakening slowed considerably, with the system maintaining a relatively constant intensity throughout the overnight period despite dry air wrapping entirely around the cyclone.

Tropical Low 09U
During early March, a monsoon trough began to develop over the eastern Indian Ocean as a pulse of the Madden–Julian Oscillation moved into the Maritime Continent, bringing increased cloudiness and convective activity to Australian longitudes. On 9 March, the BOM reported that a tropical low had begun to form to the south of Java, embedded within the monsoon trough. The atmospheric environment was assessed as being broadly unfavourable for tropical cyclogenesis; however, the BOM noted that there was a small possibility of the system briefly reaching tropical cyclone strength over the following days. The tropical low steadily organised as it tracked southwards, with deep convection developing over the low-level circulation centre and the minimum atmospheric pressure falling to 999 hPa (29.50 inHg) by 18:00 UTC on 10 March. Around the same time, the JTWC issued a tropical cyclone formation alert, citing the system's improving structure, sustained winds near gale force detected by a satellite's scatterometer instrument, and environmental conditions they assessed as being favourable for intensification.

At 06:00 UTC on 11 March, the JTWC determined that a small area of sustained gale-force winds had developed under the deep convection in the southern semicircle of the circulation, and hence classified the system as Tropical Storm 21S. Low vertical wind shear, warm sea surface temperatures and a good poleward outflow channel were forecast to remain sufficient to support the system's intensity in the short term. Weakening soon commenced, however, as the limited deep convection became sheared to the east, leaving the low-level circulation centre fully exposed. The entrainment of cold, dry air into the circulation contributed further to the weakening trend, and the central atmospheric pressure began to rise. The system fell below tropical storm intensity by 00:00 UTC on 12 March as it tracked southwestwards towards the coast of Western Australia. Despite classifying the system as a tropical low, the BOM issued a severe weather warning for a small coastal stretch of the Pilbara and Gascoyne regions, warning of the possibility of sustained gale-force winds and heavy rainfall from the system. The tropical low made landfall on the eastern coast of the Exmouth Gulf in the early hours of 13 March (local time), and began tracking towards the south. The system moved generally parallel to the western coast of Western Australia until dissipating as a tropical system by 21:00 UTC on 14 March, roughly 400 km (250 mi) northwest of Perth.

During 11 March, the tropical low passed to the west of Rowley Shoals, a group of coral reefs centred approximately 315 km (195 mi) west-northwest of Broome. Imperieuse Reef recorded maximum 10-minute sustained winds of 59 km/h (37 mph) and a gust to 74 km/h (46 mph) at around 02:00 UTC as the system was located nearby. Sustained gale-force winds were later observed on the far western Pilbara coast and nearby islands as the tropical low approached on 12 March. Barrow Island recorded 10-minute sustained winds of 76 km/h (47 mph) and a gust to 91 km/h (57 mph) at 09:00 UTC, and Thevenard Island experienced sustained winds of up to 74 km/h (46 mph) and a gust of 102 km/h (63 mph). The town of Onslow also recorded a short period of sustained gales, reaching 67 km/h (42 mph).

Tropical Cyclone Gretel
On 8 March, the BOM noted that a strong pulse of the Madden–Julian Oscillation was located in the Maritime Continent, generating increased rainfall and cloudiness, and elevating the risk of tropical cyclone formation in the waters to the north of Australia. A monsoon trough developed across the Arafura Sea the following day, and by 00:00 UTC on 10 March, the BOM reported that a tropical low had formed in the area. Originally located approximately 250 km (155 mi) west-northwest of Weipa, the tropical low began tracking southeastwards over the following days, making landfall at Aurukun on the western coast of Cape York Peninsula as a very weak system on the morning of 11 March. The tropical low re-emerged over water by 12:00 UTC on 11 March, and began to track east-southeastwards across the Coral Sea.

Initially forecast to develop steadily and reach tropical cyclone strength near Willis Island by the evening of 13 March, the system instead struggled to form a defined centre of circulation within a broad and complex area of low pressure. Eventually, a dominant circulation centre began to coalesce underneath a bloom of deep convection on the northern side of the low-pressure area, at which time the tropical low began to accelerate towards the east-southeast. The system intensified steadily thereafter, acquiring sustained gale-force winds in the northern semicircle by 12:00 UTC on 14 March. The BOM upgraded the system to a tropical cyclone three hours later, and named the storm Gretel. By this time, however, the system was quickly approaching the eastern boundary of the Australian cyclone region, leaving only a short period of time for further intensification within the basin. Gretel crossed into the South Pacific cyclone region just after 18:00 UTC on 14 March as a Category 1 tropical cyclone on the Australian scale, with maximum 10-minute sustained winds of 75 km/h (45 mph) and a central barometric pressure of 990 hPa (29.23 inHg).

The interaction between the developing tropical low and a high-pressure ridge positioned along the Queensland east coast generated a strong pressure gradient on the western side of the system. As a result, exposed sections of North Queensland's east coast and the nearby reefs and islands experienced strong winds, despite being located a considerable distance from the tropical low itself. In particular, the airport on Hamilton Island recorded several days of sustained near-gale to gale-force winds, peaking at 78 km/h (48 mph) at 17:40 UTC on 12 March, with a maximum gust of 104 km/h (65 mph) observed one hour prior. Hamilton Island also received 175.0 mm (6.9 in) of rainfall in the 72 hours to 23:00 UTC on 12 March, including 46.0 mm (1.8 in) in a 46-minute period on the morning of 11 March.

Tropical Low 11U
A low-pressure trough developed to the north of Australia during late March, associated with an increase in easterly winds from the Coral Sea. On 29 March, the BOM noted that a tropical low had begun to form within the trough, centred over the Torres Strait, near the southwestern coast of Papua New Guinea. Upon its formation, the tropical low was given the identifier code 11U by the BOM. The system meandered slowly towards the east-northeast over the ensuing days, passing into the area of responsibility of the Papua New Guinea National Weather Service. Despite tracking through a favourable environment, land interaction prevented any significant intensification from occurring, with the tropical low's circulation remaining broad and the deep convection fragmented. The system attained its peak intensity on the morning of 2 April, with maximum 10-minute sustained winds of 55 km/h (35 mph), and a minimum central pressure of 999 hPa (29.50 inHg). The tropical low dissipated on 3 April while over water in the Gulf of Papua.

Tropical Cyclone Harold
On 1 April, a tropical low formed within a monsoon trough, centered between the Solomon Islands and the eastern coast of Papua New Guinea. The environment was highly conducive for intensification, with the presence of dual-channel upper outflow, low vertical wind shear and warm sea surface temperatures. The tropical low organised rapidly as it tracked towards the east-southeast over the Solomon Sea, developing tightly curved convective banding and exceeding intensity estimates from several sources, including numerical weather prediction products, the Dvorak technique and some satellite-based analyses. The BOM upgraded the system to a Category 1 tropical cyclone on the Australian scale at 06:00 UTC on 2 April, and named it Harold. Development slowed over the following hours, with the system maintaining low-end Category 1 winds while approaching the eastern border of the Australian cyclone region. At around 21:00 UTC, Harold crossed into the South Pacific cyclone region just to the south of Guadalcanal in the Solomon Islands, and the Fiji Meteorological Service assumed responsibility for the system.

Tropical Low Jeruto
On 9 April, satellite scatterometer data indicated the presence of a broad low pressure circulation in the central Indian Ocean, near the western edge of the Australian region. The following day, the BOM reported that the system had developed into a weak tropical low, centred within a low pressure trough. The system remained mostly stationary for the next several days as low vertical wind shear, warm sea surface temperatures and good divergence in the upper troposphere allowed convection to develop over the tropical low. The low-level circulation began to consolidate into a more circular structure by 12 April, centred approximately 515 km (320 mi) to the west-northwest of the Cocos Islands. Around this time, the tropical low assumed a more consistent course towards the southwest, and crossed over the 90th meridian east into the South-West Indian Ocean cyclone region late on 13 April. The system was classified as Tropical Depression 12 by Météo-France's La Réunion office shortly thereafter, and later strengthened into Moderate Tropical Storm Jeruto.

The tropical low and its associated low-pressure trough generated light rainfall in the Cocos Islands while located nearby. The airport on West Island received 17.6 mm (0.7 in) of rain on 10–13 April. Maximum 10-minute sustained winds of 44 km/h (27 mph), gusting to 57 km/h (35 mph), were also observed for a short period on 14 April.

Tropical Depression
During late April, a strong pulse of the Madden–Julian Oscillation (MJO) tracked eastwards across the equatorial Indian Ocean, and approached Australian longitudes by early May. The presence of the MJO enhanced convective activity in the region, generating areas of increased cloudiness and rainfall across the Maritime Continent. On 1 May, a low-pressure system formed west of Indonesia's Mentawai Islands, centred within a low-pressure trough near the Equator. The system tracked east-southeastwards towards Sumatra over the following days, and on 3 May, the BOM reported that it had developed into a tropical low. Situated approximately 305 km (190 mi) southwest of the Sumatran coastal city of Bengkulu, the system was located within the area of responsibility of TCWC Jakarta, who classified it as a tropical depression. The depression began to track southwards on 4 May, and soon began to show signs of organisation, with intermittent deep convection developing over the low-level circulation centre. Citing a favourable environment for intensification, including very low vertical wind shear, anomalously warm sea surface temperatures and a good poleward outflow channel, the JTWC issued a tropical cyclone formation alert for the system on 5 May. This was later cancelled as the depression tracked westwards into an area of increasing vertical wind shear. The depression continued westwards over the following days without intensification, passing to the north of the Cocos Islands, and dissipated by 10 May.

As the system developed near Indonesia as a tropical depression on 5 May, TCWC Jakarta issued an extreme weather warning for southern Sumatra, western Java, the Bangka Belitung Islands and other nearby islands. The areas were warned to expect moderate to heavy rainfall and strong winds, as well as wave heights reaching 4 m (13 ft) in Indian Ocean waters off the south coast and in the Sunda Strait.

Tropical Cyclone Mangga
After being mostly indiscernible for the preceding week, the Madden–Julian Oscillation (MJO) redeveloped over the central equatorial Indian Ocean during mid May, and began to track towards the Maritime Continent. The return of an active pulse of the MJO led to an increase in cloudiness and convective activity across the region, and also contributed to the formation of twin cyclones, with the other being Super Cyclonic Storm Amphan in the Bay of Bengal. On 19 May, the BOM noted that a low-pressure system centred with a low-pressure trough in the far northwestern part of the basin had developed into an off-season tropical low. Situated approximately 790 km (490 mi) southwest of Padang in Sumatra, the system was located within the area of responsibility of TCWC Jakarta. Environmental conditions were assessed as favourable for tropical cyclogenesis by Météo-France and the JTWC, with warm sea surface temperatures, low vertical wind shear, sufficient moisture in the mid troposphere, and a good poleward outflow channel. Citing these conditions, the JTWC issued a tropical cyclone formation alert for the system early on 20 May.

As the tropical low tracked slowly towards the southwest, the previously fragmented deep convection began to consolidate over the centre of the broad low-level circulation. Owing to the development of gale-force westerly winds to the north of the system by the afternoon of 20 May, the JTWC upgraded the system to a tropical storm at 03:00 UTC the following day. The tropical low soon adopted a track towards the south-southeast under the influence of a high-pressure ridge to the northeast. Despite being located within an otherwise favourable environment for development, the system's low level circulation remained broad and weakly defined as moderate easterly vertical wind shear hampered the development of persistent deep convection near the centre. Supported by strong upper-level outflow, a burst of deep convection began to bloom near the centre of the struggling tropical low at around 12:00 UTC, at which point TCWC Jakarta upgraded the system to a Category 1 tropical cyclone on the Australian scale, assigning the name Mangga.

Due to the potential of the tropical low to generate for moderate to heavy rainfall, TCWC Jakarta issued an extreme weather warning for the southwestern coast of Sumatra and the westernmost part of Java on 21 May. Wave heights were also forecast to reach 6 m (20 ft) in Indian Ocean waters near the Mentawai Islands and the southwestern coasts of Sumatra and Java, and up to 4 m (13 ft) in the Sunda Strait and other areas. Severe weather warnings were later issued for the entire western area of Western Australia as the remnants of the low combined with a passing cold front to bringing damaging winds, raised dust and heavy rain in what was described as a "once in a decade" storm. Over 60,000 properties lost power in south-western Western Australia, particularly in Perth, Geraldton, Kalgoorlie and Margaret River. A wind gust of 132 km/h was reported at Cape Leeuwin.

Other systems
A weak tropical low began to develop over the eastern Indian Ocean within a low-pressure trough on 31 January, approximately 460 km (285 mi) east-northeast of the Cocos Islands and 500 km (310 mi) west of Christmas Island. The system tracked slowly towards the south-southwest over the following days with little development. The system began to gradually decay as it neared the Cocos Islands, and it dissipated as a tropical low by 4 February.

Increased winds were observed in the vicinity of the tropical low in the Cocos Islands, with a maximum wind gust of 44 km/h (27 mph) recorded at the local airport at 01:29 UTC on 2 February. In addition, 28.8 mm (1.1 in) of rainfall fell on Christmas Island from 31 January to 2 February on the eastern side of the tropical low.

Late on 6 February, the BOM noted that a tropical low had developed within a low-pressure trough near the Australian region's western border, approximately 200 km (125 mi) west of the Cocos Islands. The tropical low remained nearly stationary over the central Indian Ocean for the next few days with little development, before dissipating late on 8 February.

The Cocos Islands received 34.4 mm (1.4 in) of rainfall during the 48 hours to 03:00 UTC on 8 February when the tropical low was located nearby, as well as a maximum wind gust to 39 km/h (24 mph) at 01:44 UTC on 8 February. An extended rainfall total of 108.0 mm (4.3 in) was recorded on the islands during the five days to 03:00 UTC on 10 February as a result of the slow-moving low-pressure system and its associated trough.

The BOM indicated that a tropical low had developed on the western border of the Australian region over the central Indian Ocean at 06:00 UTC on 13 February. The tropical low was located in a concentrated area of convection being enhanced by the monsoon trough established across the South-West Indian Ocean cyclone region. Within twelve hours, the tropical had moved westwards out of the Australian region, where Météo-France's office on La Réunion assessed the system as having a low probability of intensification into a tropical cyclone.

In the midst of an active pulse of the Madden–Julian Oscillation over the tropical western Pacific Ocean, the BOM noted that a tropical low had formed within a low-pressure trough over the northeastern Coral Sea on 15 February. The slow-moving system was assessed as having a very low probability of developing into a tropical cyclone in the short term. The tropical low attained a minimum barometric pressure of 1002 hPa before moving into the South Pacific cyclone region by 17 February, where the system was designated as Tropical Disturbance 08F by the Fiji Meteorological Service.

Ex-Tropical Cyclone Irondro entered the Australian region at 06:00 UTC on 6 April, located approximately 2,575 km (1,600 mi) to the west-northwest of Perth. Upon entering the region, the Bureau of Meteorology estimated the system's central pressure as 993 hPa (29.32 inHg). At this time, the JTWC assessed the system as a low-end tropical storm, with maximum one-minute sustained winds of 75 km/h (45 mph). The system had commenced extratropical transition around the time of entering the region due to the effects of hostile vertical wind shear and sea surface temperatures decreasing below 25 °C (77 °F). Ex-Irondro was downgraded to a remnant low by 18:00 UTC.

Tropical Cyclone Rita
Beginning November 21, the Fiji Meteorological Service (FMS) began highlighting the likelihood of a tropical cyclone forming between Vanuatu and Fiji. Showers and thunderstorms began to aggregate in the region atop sea surface temperatures above 29 C in low-wind shear conditions. Imagery from microwave satellite data showed emergent rainbands wrapping towards an organising center of low pressure. Late on November 22, the FMS designated the system, now east of the Solomon Islands, as Tropical Disturbance 01F. The slow-moving disturbance tracked towards the south and southeast, steered by a broad area of high pressure. On November 23, 01F attained tropical depression status. Supported by the stout outflow of air at the upper-levels of the troposphere, shower activity became more concentrated around the center of circulation. The depression reached tropical cyclone intensity by 06:00 UTC on November 24 near the Santa Cruz Islands, earning the name Rita. A well-defined and formative eye soon developed beneath the central cloud cover. Continuing to intensify in favorable atmospheric conditions, Rita reached Category 2 cyclone strength by November 25 and Category 3 intensity six hours later. The developing eye briefly emerged on infrared and visible satellite imagery as a ragged feature at the cyclone's center, surrounded by well-defined rainbands.

Over the course of November 25, convective activity and organization slightly diminished due to an increase in wind shear, and Rita ultimately peaked as a Category 3 tropical cyclone with 10-minute maximum sustained winds of 120 km/h as well as 1-minute sustained winds up to the same intensity. Additionally, Rita reached a minimum barometric pressure of 977 mbar (hPa; 28.85 inHg). This made Rita one of the strongest first storms to form in the South Pacific since the formation of Mick in 2009, as many others were merely depressions or disturbances. It then began to track into an area unfavorable for intensification due to the presence of wind shear and cool dry air, resulting in a rapid decay of the storm's convection and a decrease of the storm's maximum winds. The FMS issued their last advisory on Rita on November 26 after the storm was downgraded to a remnant area of low pressure; at the time these remnants were slowly moving west-southwest towards northern Vanuatu. In anticipation of heavy rainfall and strong winds from Rita, the National Disaster Management Office in Port Vila, Vanuatu, issued a Red Alert for Torba Province and a Yellow Alert for Penama Province and Sanma Province. Warnings for strong winds were also issued for Shefa and Tafea provinces.

Tropical Cyclone Sarai
During December 23, the FMS reported that Tropical Disturbance 03F had developed about 630 km to the west of Tuvalu. At this time the system was poorly organised with deep atmospheric convection, displaced to the north and east of its broad and elongated low-level circulation. The disturbance was also located underneath an upper ridge of high pressure within a favourable environment for further development, with low to moderate vertical windshear and warm sea surface temperatures of 29-30 C. Over the next couple of days, the system moved southwards and gradually developed further with its overall organisation improving, before it was classified as a tropical depression by the FMS during December 25. After being classified as a tropical depression, the system continued to develop, with its outflow improving and deep convection wrapping on to the systems low level circulation center. During December 26, the JTWC initiated advisories on the depression and designated it as Tropical Cyclone 04P, before the FMS reported that the system had become a Category 1 tropical cyclone and named it Sarai. At this time, Sarai was being steered southwards to the west of Fiji, along the edge of a near-equatorial ridge of high pressure and the jetstream. Over the next couple of days, the system gradually intensified further and was classified as a Category 2 tropical cyclone during December 27, while it was located around 220 km to the west of Nadi, Fiji. During December 28, as Sarai passed about 100 km to the south of Fiji's Kadavu Island, the FMS estimated that the system had peaked as a Category 2 tropical cyclone with 10-minute sustained winds of 110 km/h (70 mph).

Due to an area of high pressure to its east, Sarai took a southerly course during its early stages as a named system. The high pressure region would later shift its orientation, causing Sarai to gradually curve towards the east. On December 27, the cyclone's winds increased further past Category 2 cyclone thresholds, with one-minute sustained winds to hurricane-force. The following day, the FMS assessed a peak intensity with ten-minute sustained winds of 110 km/h (70 mph). At the time, a large eye was evident on microwave satellite data while the storm tracked towards the southeast along the periphery of the jet stream, and remained present throughout the day. Sarai reached its lowest barometric pressure on December 29 before weakening due to increasing wind shear of 55 –, resulting in a loss of organisation. Sarai's center of circulation became displaced from the storm's convection on December 30, and the storm weakened to Category 1 strength. Its center tracked near Nukuʻalofa on December 31 while the storm's structure rapidly deteriorated, with the JTWC issuing their final advisory that day. The FMS continued monitoring the system as an ex-cyclone as the storm accelerated eastward, highlighting a low possibility for regeneration; the agency ultimately issued their final bulletin on the system on January 2.

As the cyclone passed very close to the main Fijian island of Viti Levu on December 27 and brought very heavy rainfall, the FMS warned of the probability of damaging gale-force and storm-force winds and very heavy rainfall at times, with over 2,000 people being evacuated to higher grounds in case of flooding, while commercial flights and cruises in and out of the country were delayed or cancelled as a result of these conditions. Additionally, as of December 29, 2019, 2 deaths have been confirmed related to the cyclone due to drowning in floodwaters. Damage to road infrastructure reached FJ$5 million (US$2.3 million).

Severe Tropical Cyclone Tino
On January 10, an area of low pressure formed just east of the Solomon Islands and was forecast by the FMS to track towards the southeast, exhibiting some potential to develop further into a tropical cyclone. The FMS designated the slow-moving complex of deep convection as Tropical Disturbance 04F on January 11; at the time, the disturbance was located within a moderate wind shear environment near Makira atop 31 C ocean waters. Deep convection continued to accompany the developing wind circulation over the following days as conditions grew more favourable, though the wind field remained broad and disorganised. The FMS began issuing advisories on 04F on January 14 following improvements in the disturbance's organisation. A subtropical ridge to the northeast caused 04F to track towards the east and southeast. Throughout the early part of the storm's development, a strong band of convection persisted north of the centre of circulation. Following a decrease in wind shear, the FMS upgraded 04F to a tropical depression on January 15 as it began to organize. Further intensification occurred as additional convection wrapped around the storm's centre on January 16, prompting the FMS to upgrade the system to a Category 1 tropical cyclone, giving the storm the name Tino. The next day, the storm passed near Vanua Levu and strengthened further into a Category 2 cyclone as an emerged; Category 3 intensity was reached later that day with 10-minute sustained winds estimated at 120 km/h (75 mph). However, Tino soon began to entrain dry air, resulting in a gradual decay of its convection and subsequent weakening on January 18 as the center tracked across Ha'apai. Interaction with a baroclinic zone the next day signaled the onset of extratropical transition; Tino fully completed this processes later on January 19.

Warnings for heavy rain were issued for all of the Solomon Islands and four Vanuatuan provinces by their respective National Meteorological and Hydrological Services. Similarly, a Heavy Rain Alert was issued by the FMS on January 14 for western parts of Fiji. A Tropical Cyclone Warning was subsequently issued for Rotuma on January 15, and a Tropical Cyclone Alert for the rest of the Fijian islands. Fijians were advised by the Water Authority of Fiji to boil and store drinking water in anticipation of the approaching tropical cyclone. Cruises in the area began to be cancelled on January 14. Evacuation centres were opened on January 16 in Fiji's Northern Division, as well as the division's Emergency Operations Centre. Villagers in the Udu Point region of Vanua Levu were urged to move inland due to rough forecast seas. The Labasa campus of the Fiji National University closed on January 17.

As Tino passed close to Vanua Levu, the second cyclone to pass near the nation within three weeks following Sarai, Fijian government officials called for urgent action on the 'climate crisis' in the South Pacific region. Additionally, a father and daughter were left missing after being swept away from floodwaters due to heavy rainfall generated by the system in Eastern Fiji.

Tropical Disturbance 05F
During January 24, the FMS reported that Tropical Disturbance 05F had developed about 75 km to the northwest of Pago-Pago in American Samoa. At this time, the disturbance was poorly organised with atmospheric convection located to the north of its low-level circulation center. During that day, the disturbance moved south-eastwards within an environment favourable for further development, with low vertical windshear, warm sea surface temperatures, while its outflow was enhanced by strong westerlies. As a result, atmospheric convection started to wrap into the system's consolidating low-level circulation center, which prompted the JTWC to issue a tropical cyclone formation alert on the disturbance. During the next day, the JTWC intiated advisories on the disturbance and designated it as Tropical Cyclone 12P, as the system peaked with 1-minute sustained windspeeds of 65 km/h. The system subsequently moved south-eastwards into an area of moderate vertical wind shear, while atmospheric convection became sheared and located to the northeast of the disturbance's exposed low-level circulation centre. As a result, the FMS issued their final warning on the disturbance, as it was expected to move further south into an area of high vertical wind shear. During January 26, the JTWC subsequently issued their final warning on the system after it had dissipated.

Severe Tropical Cyclone Uesi
During February 5, the FMS reported that Tropical Disturbance 06F had developed, about 775 km to the northwest of Port Villa in Vanuatu. At this time the system was poorly organised with deep atmospheric convection displaced, to the northeast of the system's weak and ill-defined low level circulation center. The disturbance was also located to the north of a subtropical ridge of high pressure, within a favourable environment for further development, with a low to moderate amount of vertical wind shear and warm sea surface temperatures of 29-30 °C. A tropical cyclone formation alert was subsequently issued by the JTWC early on February 8, as convection improved near the centre of the storm; at the time, 06F was centered 653 km northwest of Port Vila, Vanuatu. Routine advisories were initiated by the FMS the same day while 06F drifted towards the south-southwest. Convection continued to evolve at the disturbance's centre into organised banding. During February 9, the JTWC upgraded the system to a tropical storm, designating it Tropical Cyclone 15P. Later that day, the FMS named the storm Uesi, and upgraded it to a category 2 tropical cyclone.

Based on significant improvements to the storm's structure, the JTWC determined Uesi was undergoing rapid intensification. Associated showers and thunderstorms continued to coalesce within favourable atmospheric and oceanic conditions. However, the presence of dry air slowed Uesi's intensification. Uesi strengthened further into a Category 3 tropical cyclone at 18:00 UTC that day but continued to be affected by the entrainment of dry air. The cyclone developed a ragged eye 19 km early on February 11. Guided southward by the nearby influence of a subtropical ridge to its east, Uesi moved southward, passing west of New Caledonia. An increase in vertical wind shear from the northwest on February 12 caused the convective structure of the cyclone to weaken, resulting in the low-level circulation centre becoming exposed from the central dense overcast. After passing near to New Caledonia on February 11, Uesi adopted a steady south-southwestwards track towards the Australian cyclone region. At 12:00 UTC on February 12, the FMS passed primary responsibility for Uesi over to the Australian Bureau of Meteorology's (BOM) warning centre in Brisbane, who indicated that the system had weakened to a high-end Category 2 tropical cyclone. The extratropical remnants of Uesi reentered the South Pacific basin on a southeasterly heading towards South Island on February 15.

Vanuatu and the French territory of New Caledonia were threatened by Uesi along its southward trek through the South Pacific basin. Warnings were issued by the Vanuatu Meteorology and Geohazards Department for Uesi, noting the possibility of stream and coastal flooding. Météo France (MFR) issued thunderstorm and rain warnings for four municipalities in New Caledonia on February 9, and later raised warnings to an orange alert for six the following day. Ferry and bus services in several New Caledonian communes were suspended. Flights serviced by Air Calédonie were also delayed. The first accommodation centers in the French territory were opened on February 10. One person was injured while securing their roof in preparation for the storm. Uesi passed between 100 – west of Belep, New Caledonia, on February 11, bringing heavy rains and strong winds. MFR stations recorded up to 300 mm of rainfall in Poum over a 48-hour period; this was roughly equal to two months of average rainfall. Flooding from Uesi's rainfall blocked travel between Poum and Koumac, as well as other bridges throughout the territory. Several routes to Dumbéa were blocked by floodwaters. Gusts of up to 120 km/h impacted New Caledonia's central mountain range. Power outages afflicted at least 3,900 households serviced by EEC and Enercal and over 5,000 overall. At least 565 homes lost power in Hienghène and Ponérihouen. All warnings for New Caledonia were lifted by the morning of February 12. Rough surf generated by Uesi forced the closure of beaches in Gold Coast, Queensland beginning that day. The large extratropical stage of Uesi produced 6 – waves off the northwestern shores of South Island.

Tropical Disturbance 07F
During February 14, the FMS reported that Tropical Disturbance 07F had developed, about 490 km to the northeast of Funafuti in Tuvalu. The disturbance developed within a broad trough formed by a complex interaction between an amplified South Pacific convergence zone, a monsoon trough and a westerly wind burst in the region. Despite lacking a clear wind circulation within a chaotic environment—the JTWC initially considered the disturbance to be a hybrid tropical system rather than a tropical cyclone—the region's warm sea surface temperatures and low wind shear were supportive of further organisation. However, development was slow and convection remained displaced from the center of circulation three days later. After an extended period of slow movement, 07F accelerated south of Samoa on February 19. Over the following days, the system tracked towards the east-southeast with little development. 07F turned towards the southwest by February 20, where strong wind shear began to degrade the convective structure of the system. The FMS issued the final advisory on the system on February 21 while it was passing to the south of Niue.

The U.S. Federal Emergency Management Agency sent seven representatives to American Samoa in advance of the disturbance. Before 07F's arrival, a moisture-laden convergence zone had already been affecting Samoa with heavy rainfall and high winds. Warnings from the Samoa Meteorology Service for rain, wind, and flooding were in effect for Savai'i and Upolu, resulting in cancellations of ferry services. While the threat of both 07F and nearby 08F lessened on February 18, warnings remained posted due to the persistence of the active convergence zone. The Ministry of Education Sports and Culture closed schools between February 18–19 in response to the inclement conditions. Roads in three villages in Apia were flooded by rains associated with 07F. Power outages affected Tutuila in American Samoa, where airports closed as the storm passed. Further southeast, in the Cook Islands, a civil defense emergency was declared. All schools were closed in Rarotonga. Large waves along the island's coast forced the closure of the seawall road.

Tropical Disturbance 08F
On February 17, the FMS noted the formation of Tropical Disturbance 08F between American Samoa and Niue. The system was poorly organised, with a high wind shear environment displacing convection to the northeast of the low-level center of circulation as the disturbance moved southeast to east-southeast. The JTWC considered the disheveled cyclone as subtropical in nature, remaining in an environment hostile to increased organisation. By February 18, the JTWC declared the disturbance to have dissipated. Later that day, the center of 08F continued past the 25th parallel south, leading the FMS to issue their final tropical disturbance summary on the highly sheared system.

Tropical Cyclone Vicky
The FMS analysed the formation of Tropical Disturbance 09F on February 19 near Wallis and Futuna, positioned within an area of low wind shear and divergent flow aloft. The east-southeastward-moving storm was upgraded to a tropical depression the next day, prompting routine advisories from the FMS. Developing rainbands quickly organised atop the newly formed and compact low-level circulation center. 09F tracked near Samoa on February 20 with maximum sustained winds of 55 km/h (35 mph), with the center later passing just south of Tutuila in American Samoa. Continuing to track towards the east-southeast, the depression strengthened into a Category 1 tropical cyclone later that day, receiving the name Vicky. Though the cyclone's rainbands expanded further, the storm's convection remained disorganised. Despite warm ocean waters and a conducive environment aloft for outflow, strong wind shear led to a deterioration of Vicky's shower activity. On February 21, the FMS issued their final advisory on Vicky once it transitioned into an ex-tropical system.

Flights to Pago Pago were cancelled indefinitely by Samoa Airways, with delays impacting Faleolo International Airport. Non-essential government employees in American Samoa were released from work on February 20 as Vicky passed to the south, suspending United States Postal Service and United States Department of Veterans Affairs operations. Vicky produced damaging winds and heavy rain in the Samoan islands as an intensifying system. Brief power outages affected parts of Samoa early on February 21. The combination of Vicky and two other tropical disturbances resulted in a peak rainfall of 203.2 mm in Le'auva'a between February 17–20. A 120 km/h (75 mph) gust was measured in Pago Pago International Airport in American Samoa and sustained winds of 85 km/h (50 mph) were observed in Tutuila. One buoy off Aunu'u measured 3.7 – seas due to Vicky.

Tropical Cyclone Wasi
During February 21, the FMS reported that Tropical Disturbance 10F had developed, about 145 km to the north of Mata Utu on the island of Wallis. The disturbance was located within an area of low vertical windshear while atmospheric convection persisted over and had started to wrap into the systems low-level circulation centre. 10F was upgraded to a tropical depression 12 hours after its initial designation. Continuing to organise throughout the day, the system was upgraded to Tropical Cyclone Wasi by February 22 while centred west of Samoa. A transient eye-like feature emerged on satellite imagery early on February 22, suggesting a cyclone stronger than its organisation suggested. While the cyclone was initially highly compact and within favourable conditions, interaction with the nearby insular landmasses suppressed Wasi's convection. Continued interaction ultimately caused Wasi to weaken and become increasingly disorganised after passing south of Samoa. Accelerating towards the south-southeast, convective activity associated with Wasi became limited to the cyclone's eastern half, eventually exposing the low-level centre of circulation on February 23. This circulation quickly slackened during the day.

The Samoa Meteorology Division issued a Category 1 Tropical Cyclone Warning for Samoa on 22 February, prompting the activation of the country's National Emergency Operations Centre. Heavy rain and flood warnings were also in effect for Samoa. Wasi was the second tropical cyclone to affect the Samoan islands in two days. Downpours from Wasi spread over the islands of Upolu and Savai'i. Two rivers in Savai'i flooded their banks and inundated adjacent roads. River and small stream flooding was also documented in Upolu. In American Samoa, 50 mm (2 in) of rain fell over a 12-hour span. Gusts to 69 km/h were reported at Pago Pago International Airport, which had suspended operations during Wasi's passage. Two homes were destroyed and six sustained major damage from the combined effects of Cyclones Wasi and Cyclone Vicky in American Samoa, which had struck the territory in the same week. Minor damage was inflicted to another 58 homes. A gale warning was issued by the FMS for Niue that was later cancelled upon Wasi's dissipation.

Tropical Cyclone Gretel
During March 15, Tropical Cyclone Gretel moved into the basin from the Australian region, about 620 km to the northwest of Nouméa in New Caledonia. Gretel continued to organise upon its entrance into the basin, exhibiting well-formed rainbands within a low-shear environment. Forced southeast by a nearby subtropical ridge, The storm passed 150 km south of New Caledonia on March 15. During this time, an eye-feature was noted by the JTWC on microwave-wavelength satellite imagery. The FMS upgraded Gretel to a Category 2 cyclone at 12:00 UTC that day. However, the storm's convective activity soon began to diminish as dry air began to permeate the low-level circulation center. The addition of strong vertical wind shear caused Gretel's remaining showers and thunderstorms to dislocate from the central vortex. Gretel quickly developed frontal features on March 16—a sign of extratropical transition.

Level 1 cyclone alerts were issued for New Caledonia's North and South provinces on March 15 and were lifted by the following morning. Shelters were opened throughout the territory in anticipation of Gretel's passage. Air Calédonie cancelled some of its March 15–16 flights; some Aircalin were also cancelled or rescheduled. All Raï bus routes were cancelled for March 15. Several ports were closed and the Ouaième–Hienghène ferry was suspended. Classes at the University of New Caledonia on March 16–17 were closed at their Nouméa and Koné campuses; the Collège de Païamboué also closed its classes. Power outages affected the greater Nouméa area on New Caledonia, particularly in Le Mont-Dore and Savannah sur Mer. Across three municipalities, 791 homes were without power by the evening of March 15, and ultimately at least 6,931 electricity customers lost power during Gretel's passage. Some roads were blocked by downed trees. Gretel's effects disrupted some municipal elections, flooding a polling station and preventing voter travel in some municipalities; voter turnout was diminished relative to the previous elections in 2014. Northern parts of New Caledonia received 50 – of rain over a six-hour period, and 100 – of rain overall was recorded on the northern and southern extents of Grande Terre. Floods overtook a bridge between Pouébo and Ouégoa. Rough seas grounded a barge in Nouville. The Australian territory of Norfolk Island recorded maximum 10-minute sustained winds of 57 km/h (35 mph) and a maximum gust to 83 km/h (52 mph) on March 16.

Severe Tropical Cyclone Harold
During April 3, Tropical Cyclone Harold moved into the basin from the Australian region, as a Category 1 tropical cyclone on the Australian scale. Atmospheric conditions were supportive of further intensification within the South Pacific as the storm tracked towards the southeast. On April 3, Harold began to quickly gain in organisation and intensity, developing tightly wound rainbands and a pinhole eye. Harold rapidly intensified into a Category 3 severe tropical cyclone by April 4; Category 4 intensity was reached by 12:00 UTC that day, with Harold exhibiting maximum ten-minute sustained winds of 165 km/h (105 mph). The JTWC assessed Harold three hours later as having one-minute sustained winds of 215 km/h (130 mph), equivalent to a Category 4 hurricane on the Saffir–Simpson scale. Concurrently, an extension of an area of high pressure to Harold's east caused the storm's track to slow and curve increasingly southward. Afterwards, the storm recurved eastwards and accelerated before turning east-southeastwards. On the next day, the storm intensified into a Category 5 Severe Tropical Cyclone, the highest rating on the Australian scale. Later that day, at 1:00 P.M. local time, the storm made landfall on Espiritu Santo. At landfall, the storm had 10-minute winds of 215 km/h (130 mph). Intensification continued and by 12:00 UTC, it reached peak intensity as a Category 5-equivalent cyclone on the Saffir-Simpson scale, with 10-minute winds of 230 km/h (145 mph) and a minimum barometric pressure of 920 mbar. It maintained the intensity for only 6 hours before weakening back to a Category 4-equivalent cyclone. The storm began an Eyewall replacement cycle. And thus, both warning centers downgraded the system. After the cyclone was completed, a new eye formed. Thus, the FMS upgraded Harold to a Category 5 severe tropical cyclone for the second time. Later that day, it reached Category 4 status on the SSHWS yet again. On April 8, the storm passed just south of Fiji and passed over Kadavu Island. The system finally began to weaken as it accelerated towards Tonga. Later that day, the storm passed just 100 mi (165 km) south of Tongatapu, the main island of Tonga, as a Category 3-equivalent cyclone. On the next day, the storm began an extratropical transition while it moved into MetService's area of responsibility. The JTWC subsequently issued its final advisory on Harold, as it was expected to gain frontal characteristics and complete its extratropical transition within 12 hours. MetService subsequently declared Harold to be an extratropical cyclone during April 10, before the system was last noted during the following day around 1500 km to the southwest of Adamstown in the Pitcairn Islands. Cyclone warnings were issued for the entirety of the Solomon Islands as Harold approached on April 3. Strong winds blew down trees in Honiara, causing power outages and blocking roads. Rainfall associated with the passing storm also caused flooding, forcing dozens of families out of their homes. A ferry repatriating 738 people from Honiara to Malaita Province amid the COVID-19 pandemic encountered the storm in the Ironbottom Sound; 28 people were washed overboard by the waves. All but one of the people are presumed dead.

On April 3, the Vanuatu National Disaster Management Office (VNDMO) issued a Yellow Alert for Torba and Sanma provinces in Vanuatu. The Vanuatu Meteorology and Geo-Hazards Department also issued a tropical cyclone warning for these areas. The yellow alert was upgraded to a red alert on April 4, while yellow alerts were also issued for Malampa and Penama provinces. Red alerts eventually encompassed Malampa, Penama, Sanma, and Torba provinces, with a yellow alert for Shefa Province. The VNDMO advised for all residents under the red alert to remain indoors. All COVID-19 preparedness activities were suspended to facilitate preparations and evacuations for Harold. Harold was the first severe tropical cyclone to strike Vanuatu since Cyclone Pam in 2015, bringing gusts above 275 km/h (170 mph), 250–450 mm (10–18 in) of rain, and a storm surge of 0.8 m (2.6 ft) causing catastrophic damage, torrential flooding and communication disruptions and plunging Vanuatu into a blackout.

In Fiji, heavy rain alerts were issued for the western half of Viti Levu, Kadavu, and the Mamanuca and Yasawa islands on April 6. Storm warnings were later put in effect for the areas under a heavy rain alert, in addition to the Lomaiviti Islands. The highest warning, a hurricane warning, was issued for Kadavu and Ono-i-Lau on April 7. The Fiji National Disaster Management Office (FDNMO) activated their Emergency Operations Centre to streamline preparations and evacuations. A total of eighty-five shelters were opened, with at least two in each of Fiji's four districts. All village headmen and community leaders were directed to. All COVID-19-related activities were also cancelled in order to prepare for the impact of Harold. Early on April 7, the storm began affecting the nation with gusty winds, moderate coastal flooding, and storm surge. These conditioners worsened as the storm approached. In contrast to the forecasts, the passed only to the south of Fiji and thus, the northern islands received little damage. Kadavu Island was hit the worst as the storm's center passed over the island. Many infrastructures were damaged or destroyed due to the strong wind and storm surge.

Other systems
During December 19, the FMS reported that Tropical Disturbance 02F had developed about 55 km to the northeast of Tau in American Samoa's Manu‘a Group. At this time, the system was poorly organised with atmospheric convection located to the east of the storms low level circulation center. Over the next few days, the system moved south-westwards within an area that was marginally favourable for further development, with good poleward outflow and warm sea surface temperatures offset by low to moderate vertical wind shear. However, it failed to develop any further and was last noted by the FMS during December 23, after it had lost its tropical characteristics and became extratropical.

Zone of Disturbed Weather 01
In mid-July, a broad wind circulation developed over the central Indian Ocean, accompanied by deep convection. Some computer models suggested the possibility of a southern segment of this system organising into a tropical cyclone; Météo-France (MFR) initially estimated a "very low" chance of a moderate tropical storm materialising from the large circulation near Diego Garcia. Due to strong wind shear, the environment remained unfavourable for tropical development. On 22 July, Météo-France began monitoring the system as a zone of disturbed weather; the system's forward motion was initially southward. A temporary decrease in wind shear on 23 July provided a brief period conducive for tropical development, and the system strengthened to its peak winds of 45 km/h (30 mph) that day. However, the disturbance's centre of circulation remained ill-defined and lacking showers and thunderstorms. Although the disturbance was forecast to initially strengthen into a tropical storm, an increase in wind shear prevented the storm from consolidating further about the centre of circulation and caused the overall wind field to disorganise. The system curved towards the west on 24 July and eventually degenerated into a remnant circulation northeast of Rodrigues by the 25 July; these remnants persisted for another day before dissipating entirely.

Tropical Cyclone Belna
Météo-France began highlighting the potential for tropical cyclone development in their daily bulletins on 25 November, noting an increase in shower activity west of the Seychelles. Aided by the passage of a Kelvin wave and a favourable window in the Madden–Julian oscillation, a broad trough of low pressure began to take shape within the storm activity, extending across the equator. Projections from computer models remained in disagreement over the system's future, complicated by the concurrent development of a tropical disturbance in the northwestern Indian Ocean along the same trough. A loosely-defined wind circulation was detected 263 km south of Mahe, Seychelles on 29 November, offset from convection. Over the following days, this circulation tightened within an environment moderately conducive for tropical development. Météo-France declared the system as a zone of disturbed weather on 2 December; at the time the system had drifted west from its point of origin. Although the storm was better organised and the environment conducive for intensification, the storm's wind field initially remained elongated and rainfall remained north of the storm's centre. The disturbance become a tropical depression on 5 December, attended by an increase in rainbands and the return of convection at the center of circulation; at 18:00 UTC that day, the system was upgraded to Moderate Tropical Storm Belna. Belna was upgraded further to severe tropical storm status early on 6 December. Around the same time, a cloud-obscured eye briefly became apparent in microwave satellite imagery. Due to a strengthening area of high pressure to its east, Belna began to curve from its initial westward drift to a more directed southwestward trajectory. After a brief period of strengthening, Belna's central dense overcast remained largely unchanged throughout 6 December before signs of resumed intensification emerged by the day's end, followed by the development of another eye. With the storm's eye becoming better defined, MFR upgraded Belna to a tropical cyclone early on 7 December. Hot towers were detected atop and within the storm's radius of maximum winds, suggesting the onset of a more accelerated rate of intensification. On 9 December, Belna made landfall near Mayotte and soon began to rapidly weaken, with the winds dropping below tropical-storm-force on the next day. The system dissipated late on 11 December over Haute Matsiatra.

Météo Madagascar first issued green alerts for the Madagascan districts of Diana, Sava, and Sofia on 4 December based on a high probability of Belna impacting northeastern Madagascar. Accordingly, cyclone response measures were activated by the National Office for Risk and Disaster Management and humanitarian organisations across northern Madagascar. Green alerts were later extended to encompass five districts. A cyclone pre-alert was issued for Mayotte on 6 December, succeeded by an orange alert the following day. Civil security personnel from mainland France and Reunion, some from the National Gendarmerie, were sent to Mayotte to aid storm preparation efforts there. Shelters were opened in several Mayotte communes on 7 December. The National Office for Risk and Disaster Management and 11 humanitarian agencies were active in northern Madagascar by 9 December. Belna's effects in Mayotte were minimal as the storm passed 100 km to the east. The worst effects of Belna in Madagascar occurred in Soalala, where the storm made landfall. The roofs of 80% of residences and government buildings in the city were damaged by Belna's winds. Damage to homes displaced 1,400 people in Soalala and another 900 throughout Madagascar. Extensive flooding also affected both Soalala and Antsiranana. Belna's impacts in Madagascar killed nine people and caused at least US$25 million in economic losses.

Very Intense Tropical Cyclone Ambali
While Belna was gradually developing out of an extended trough of low pressure, another area of convection formed along the same trough between the Seychelles and the Chagos Archipelago in early December. The system organised quickly, attaining formative rainbands around a coalescing centre of circulation on 3 December. At 06:00 UTC, the system was classified as a Zone of Disturbed Weather. A day later, the system was upgraded to a tropical depression following a significant increase in convection near its centre. Steered by a high-pressure area centred over the southern Indian Ocean, the tropical depression moved south. The quick organisation continued into 5 December, and MFR named the system Moderate Tropical Storm Ambali as a central dense overcast emerged; Ambali intensified into a Severe Tropical Storm a few hours later. Buoyed by a highly favourable environment with waters between 29 –, explosive intensification ensued, accompanied by the formation of an eye. At 18:00 UTC on 5 December, MFR upgraded Ambali to intense tropical cyclone status following a sharp 75 km/h (45 mph) increase in the storm's winds in 3 hours. The cyclone was highly compact, with a distinct eye 15 km (9 mi) in diameter surrounded by cold cloud tops.

Six hours later, Ambali was reclassified as a very intense tropical cyclone, the highest rating on the MFR's intensity scale and the first in the basin since Fantala in 2016. The agency estimated maximum 10-minute sustained winds of 220 km/h (140 mph) and a minimum pressure of 930 mbar (hPa; 27.46 inHg); concurrently, the Joint Typhoon Warning Center (JTWC) assessed peak 1-minute sustained winds of 250 km/h (155 mph), making Ambali a high-end category 4-equivalent on the Saffir–Simpson scale. The cyclone's eye had contracted further to a diameter of 9 km (5 mi) early on 6 December at the time of peak intensity. Based on JTWC data, Ambali's winds increased by 185 km/h (115 mph) in 24 hours, marking the fastest 24-hour intensification recorded in the Southern Hemisphere since 1980 and topping the old record set by Cyclone Ernie in 2017. A gradual weakening trend soon succeeded the rapid intensification episode as indicated by a clouding-over of the small eye. Within a few hours of Ambali's peak strength, the eye was no longer apparent on infrared satellite imagery; dry air became wrapped close to the core of the cyclone's compact circulation. Impaired further by an increase in wind shear, Ambali's strength quickly diminished throughout 6 December, and by the following day, its winds fell below tropical cyclone thresholds. Despite otherwise inhibiting environmental factors, the eye reappeared for a two-hour period before fully succumbing to the dry air and 55 km/h (35 mph) wind shear. Rapid weakening soon proceeded, and by mid-day on 7 December, the storm's coldest cloud tops were displaced east of the center of circulation; Ambali's motion also became erratic as winds in the lower levels of the troposphere began to govern its track. On 8 December, Ambali degenerated to a remnant low and MFR issued their last advisory on the dissipating system.

Tropical Cyclone Calvinia
The origin of Calvinia can be traced back to an area of persistent showers and thunderstorms southwest of Diego Garcia first noted by the JTWC on 16 December. The system featured a loosely-defined circulation upon designation, but computer models indicated that tropical cyclogenesis intermediately was unlikely. The storm complex drifted southward over the next two days, and an increase in organisation briefly prompted the issuance of a Tropical Cyclone Formation Alert (TCFA) on 18 December before an increase in wind shear cut development of the system short, leading to alert's cancellation despite the system producing storm-force winds. The system then slowly curved to the west towards Madagascar, eventually moving into a much more favorable environment enhanced by a passing Kelvin wave by 25 December. Two days later, MFR designated the system as a Zone of Disturbed Weather; the disturbance was initially broad and had two areas of rotation. The next day, MFR upgraded the system to a Tropical Depression while the JTWC issued a second TCFA. Tracking southward, the depression strengthened and became a Moderate Tropical Storm on 29 December, gaining the name Calvinia.

Dry air and wind shear afflicted the nascent storm early in its development, limiting convection to the southern half of Calvinia's circulation. The storm remained asymmetric but showed signs of improvement on 29 December as the environment became more favourable for intensification, with rainbands redeveloping near the center of the storm. Concurrently, Calvinia turned towards the southwest and slowed down as it neared Mauritius. The next morning, a small eye emerged within the quasi-stationary Calvinia on radar imagery from the Mascarene Islands, allowing the MFR to upgrade Calvinia to a Severe Tropical Storm that day. The eye was later evident on satellite imagery, indicative of continued intensification. After the eye had collapsed yet again, an area of high pressure to Calvinia's southeast then began to steer the storm slowly towards the south and away from the Mascarene Islands on 30 December. Shortly after it began to track away from Mauritius, the storm intensified further into a Category 1 hurricane-equivalent storm and another eye began to appear on satellite imagery on 31 December. Shortly after, the MFR also upgraded Calvinia to a tropical cyclone. Not too long after intensifying, the storm accelerated southwestwards and significantly weakened on 1 January. As a result, the MFR issued their final advisory on the system as it turned extratropical.

All the three major Mascarene Islands were placed under a pre-cyclonic alert on 29 December. Mauritius Meteorological Services issued a class III warning for Mauritius on 29 December, indicating the forecast onset of 120 km/h wind gusts. Several key services in Mauritius were closed ahead of Calvinia's approach, including Sir Seewoosagur Ramgoolam International Airport and the Port Louis Harbour amid the country's peak tourism season, effectively suspending external trade with Mauritius. The Stock Exchange of Mauritius suspended operations, and most other shops and businesses in Port Louis also closed. Air Mauritius postponed all of its flights indefinitely. Evacuation shelters on Mauritius housed 298 refugees during the storm, with a total of 168 shelters opened. The centre of Calvinia was 60 km from Mauritius at its closest approach on 31 December. Stormy conditions prevailed on the island, causing flooding in some areas. Power outages affected 6,000 families in Union Vale and Ferney. Rains from Calvinia caused flooding in southern Réunion, blocking roads in Saint Louis and L'Étang-Salé. The storm also caused minor damage on the island, knocking down trees and power lines. Water utility company Sudéau reported several incidents to its water distribution systems during the storm. A 325 mm-rainfall total was recorded in Dimitile, while a peak wind gust of 122 km/h was measured in Plaine des Cafres.

Tropical Depression 05
In mid-January 2020, a monsoon trough began to produce persistent convection over the southwestern Indian Ocean near the Chagos Archipelago. An elongated wind circulation slowly developed within this aggregation of storms moving towards the southeast. MFR classified the system as a Zone of Disturbed Weather on 19 January and initiated advisories two days later. Due to strong wind shear and low-level convergence, conditions were unfavourable for substantial intensification. Strong convective bursts occurred in response to an attenuation of wind shear, leading the MFR to reclassify the system to a Tropical Disturbance on 22 January; nonetheless, the system remained generally disorganised as the center of circulation remained near the edge of the associated shower activity. The JTWC classified the asymmetric disturbance, now 1315 km east of Mauritius, as a tropical storm later that day. On 23 January, the MFR upgraded the system to a tropical depression as convection continued to strengthen further in tandem with the diminishing of vertical wind shear; however, this period of strengthening was cut short by the storm's trajectory towards the subtropical jet stream. Coupled with a return of wind shear and cooling sea surface temperatures, shower activity associated with the storm quickly diminished; both the MFR and JTWC issued their final advisories on the storm on 23 January.

Moderate Tropical Storm Diane
As early as 11 January, long-range ensemble forecast guidance from the European Centre for Medium-Range Weather Forecasts suggested the possibility of a storm forming over the Mozambique Channel. A low-pressure area eventually formed over southern Africa by 18 January, and was forecast by the MFR to develop within the channel as part of a complex series of developing low-pressure minima along a monsoon trough extending across Madagascar. A centre of circulation of monsoonal character began to develop on 22 January between Juan de Nova Island and the western Malagasy coast, prompting the MFR to designate the system as Zone of Disturbed Weather 06. The incipient disturbance tracked eastward across Madagascar, maintaining a corridor of strong winds. By the afternoon of 23 January, the centre of the system emerged over the Indian Ocean. The system then began to slowly consolidate with the aid of warm ocean waters, with the MFR upgrading it to a tropical depression on 24 January. The presence of a trough to the south and an equatorial ridge to the north produced a westerly flow in the region, resulting in an unusual eastward track towards the Mascarene Islands. Based on satellite analysis and scatterometer data, the depression strengthened further near Mauritius to a Moderate Tropical Storm by 18:00 UTC on 24 January and received the name Diane. The centre of Diane tracked 30 km north of Mauritius roughly three hours later. Diane's southeasterly motion lessened the inhibitory effects of wind shear, allowing the storm to intensify as indicated by improved convection on the storm's southern side. Deep convection around the central dense overcast remained persistent, and as a result MFR upgraded Diane to Severe Tropical Storm status on 26 January. Diane continued southeast throughout the day, and a combination of wind shear and interaction with a baroclinic zone caused Diane to begin losing tropical characteristics. Much of Diane's convection eventually diminished, and Diane was reported to have fully lost its tropical characteristics later on 26 January, leading MFR to issue its final tropical advisories on the system. The extratropical remnants of Diane continued to persist for an additional two days, curving towards the southwest before MFR issued its last bulletin on the system on 28 January.

Diane's precursor disturbance worsened flood conditions in Madagascar, producing heavy rainfall; 129 mm of rain fell in Antsohihy amid widespread rainfall totals of 50 mm. Effects were most prevalent in seven districts in northern Madagascar, where nearly 107,000 people were affected. Thousands of hectares of land and more than 10,600 homes were inundated by floodwaters; of the homes, 146 were destroyed. Thirty-one people were killed, primarily by drowning, according to the Bureau National de Gestion des Risques et des Catastrophes. The Malagasy government declared a state of emergency for Madagascar on 24 January. A yellow cyclone pre-alert was issued by MFR for Reunion on 23 January, eventually superseded by an orange pre-alert. The University of Reunion Island closed all of its campuses ahead of Diane. Southern parts of Reunion were most heavily affected by Diane's rainfall. In Les Makes, 460 mm of rain was recorded. Several rafts at river crossings were flooded, truncating roads. A level 3 alert was issued for Mauritius and a level 1 alert for Rodrigues on 24 January; these alerts were lifted the next day. In Mauritius, 1,121 people sought refuge in 23 evacuation centres. Sir Seewoosagur Ramgoolam International Airport closed for 19 hours as Diane passed to the north. Flights to Rodrigues were cancelled on 25 January.

Moderate Tropical Storm Esami
Beginning on 16 January, MFR began to note the potential of a disturbance forming east of Madagascar during the same active period that would eventually spawn both Tropical Depression 05 and Moderate Tropical Storm Diane. A convergence zone had persisted over the region and was expected to evolve into a monsoon trough from which tropical cyclones could develop. On 22 January, a low-pressure area with multiple circulation centres developed near the Mascarene Islands between the weakening Tropical Depression 05 and then-Tropical Disturbance 06 (which would later become Moderate Tropical Storm Diane). The MFR did not forecast tropical cyclogenesis at the time due to the presence of unfavourable atmospheric conditions. However, a more well-defined circulation quickly took hold with an associated curved rainband appearing on the system, leading MFR to designate the system as Tropical Disturbance 07 between Mauritius and Rodrigues on 23 January. Due to westerly flow in the mid-troposphere, the newly classified disturbance took an east-southeasterly course. Though the storm's convection was variable, wind shear limited convection to the northern quadrants of the circulation. The disturbance was upgraded to a Tropical Depression based on scatterometer data later that day.

It continued to intensify, developing a quickly evolving and compact area of central overcast, receiving the name Esami as it intensified into a Moderate Tropical Storm on 25 January. Dry air and wind shear generated by the nearby Moderate Tropical Storm Diane to the storm's west resulted in Esami maintaining a lopsided appearance with the strongest winds and convection limited to the eastern part of the wind circulation. This dry air was later entrained to the centre of Esami, exposing the center of circulation and displacing convection from it. According to MFR, Esami's 10-minute maximum sustained winds topped out at 75 km/h (45 mph) early on 25 January. The passage of a trough to Esami's south drew the storm increasingly poleward, causing its track to curve towards the south-southeast. On 26 January, Esami began to interact with a baroclinic zone associated with the subtropical jet stream, causing Esami to lose its tropical characteristics. At 12:00 UTC that day, MFR re-classified Esami as a post-tropical depression.

Moderate Tropical Storm Francisco
Towards the end of January and the beginning of February, a convectively-active monsoon trough persisted across much of the southwestern Indian Ocean, generally northeast of Madagascar. Regions of rotation began to develop within the complex of showers by 1 February, and due to the favourable atmospheric conditions, MFR highlighted the possibility of tropical cyclogenesis in three locations. Later that day, the JTWC began monitoring a more coherent area of convection associated with loosely-defined rotation approximately 900 km southeast of Seychelles. Slow consolidation occurred as the complex of showers and thunderstorms meandered southwards near the Chagos Archipelago. MFR classified the system as a Zone of Disturbed Weather on 3 February, and advisories were initiated the next day following detection of an elongated circulation alongside increased convection and wind curvature. The storm took an initially southwest track before curving southeastwards along the periphery of a nearby subtropical ridge. With improving organisation, the disturbance was upgraded to a Tropical Depression on 4 February during a brief timeframe supportive of intensification.

On 5 February, MFR upgraded the system to a Moderate Tropical Storm as a strong curved rainband developed; following routine, the Mauritius Meteorological Services named the storm Francisco. Although Francisco's cloud pattern evolved into a central dense overcast, the 75 km/h (45 mph) 10-minute sustained wind assessed upon its upgrade to a tropical storm was ultimately the peak intensity of Francisco's first iteration. Northwesterly vertical wind shear accompanied by dry air in the mid-levels of the troposphere soon began to afflict the tropical storm, making its wind circulation increasingly ill-defined. The wind shear caused the bulk of Francisco's deep convection to shift southeast away from the center of circulation. Although gale-force winds were still present, Francisco was downgraded to a Zone of Disturbed Weather on 6 February as the circulation center became increasingly difficult to identify. Unfavourable atmospheric conditions remained in place throughout most of the day, but an attenuation of wind shear allowed some maintenance of the storm's convection. MFR issued a final bulletin on Francisco on 7 February following the disappearance of most of the storm's convection. However, the system's wind circulation remained well-defined as the remnants curved west.

Over the following week, Francisco's remnants continued west to west-northwest, and dry air was initially forecast to prevent any deep convection from reemerging. However, improved atmospheric conditions allowed for a burst of convection atop a well-defined circulation on 13 February as it was just east of Madagascar, prompting MFR to reinitiate advisories on the system as Tropical Depression Francisco. The regenerated storm tracked slowly south-southwest and quickly acquired compact rainbands, becoming a Moderate Tropical Storm the following day. An eye-like feature was observable on microwave satellite imagery around the time Francisco reached its peak strength with sustained winds of 85 km/h (50 mph) on 15 February. Later that day, Francisco made landfall on the eastern coast of Madagascar near Mahanoro and quickly weakened over land; satellite data and surface observations suggested that any low-level circulation abated by 16 February. Warnings for heavy rainfall were issued for several Malagasy districts as Francisco's second iteration approached from the east; red vigilance advisories were issued for four Malagasy districts. The Indian Ocean Regional Intervention Platform in Reunion provisioned relief supplies for shipment to Antananarivo with availability to 650 families. Persistently heavy rains inundated areas of Toamasina, submerging roads. Entire neighborhoods were flooded in Mahanoro and other nearby districts. A child was killed in Vatomandry following the collapse of a house.

Intense Tropical Cyclone Gabekile
Due to the anticipated convergence of favourable environmental parameters for development, MFR's tropical weather discussions began to highlight the possibility of a storm gradually developing in the eastern part of the South-West Indian Ocean basin on 9 February. A broad circulation in the lower troposphere and embedded within a monsoon trough began to take shape in this region on 12 February. The MFR designated the burgeoning system as a Zone of Disturbed Weather at 18:00 UTC on 13 February and began issuing advisories a day later. The presence of a subtropical ridge to Gabekile's east led to the storm taking a predominantly southward track. Although its associated showers were initially disorganised, a burst of convection early on 15 February allowed the disturbance to quickly develop. The system was named Gabekile by the Mauritius Meteorological Services upon strengthening into a Moderate Tropical Storm at 06:00 UTC on 15 February. Gabekile was upgraded to a Severe Tropical Storm six hours later as its convection evolved into a central dense overcast with a nascent eye. Aided by conducive environmental conditions, Gabekile intensified into a tropical cyclone by 16 February, presenting a small eye surrounded by a central region of cold cloud tops. Its maximum sustained winds were estimated at 130 km/h (80 mph) with gusts to 185 km/h (115 mph).

After intensifying from a tropical depression to a tropical cyclone in 24 hours, Gabekile held tropical cyclone intensity for less than 12 hours. Cloud tops warmed following its peak intensity and the western eyewall degraded, leading to a decrease in the cyclone's analysed strength. By 12:00 UTC on 16 February, Gabekile had weakened to a Severe Tropical Storm coincident with the eye's dispersal on both infrared and visible satellite imagery. The weakening storm's convective structure fluctuated considerably throughout the day in response to an increase northwesterly wind shear, accentuated by an intrusion of dry air into the storm's circulation. Concurrently, Gabekile location in a barometric col—a region with weak steering currents—caused the storm's initially southward trek to become nearly stationary. Gabekile's winds diminished to Moderate Tropical Storm-force on 17 February as the continued presence of dry air dissipated most of the associated shower and thunderstorm activity. MFR downgraded Gabekile to a remnant area of low pressure on 18 February once the center of circulation became devoid of prolonged convection. Gabekile's remnants drifted southward and acquired post-tropical characteristics upon interacting with an upper-level trough on 19 February.

Intense Tropical Cyclone Herold
Towards the beginning of March, a diffuse low-pressure system persisted for several days near Tromelin Island, remaining nearly stationary with an occasional drift towards the north or west. Though conditions were initially favourable, the further development of the system was slowed by its large size. An influx of dry air and strong wind shear muted convective activity around the low-pressure area, eventually leading to its dissipation on 4 March. However, convection unexpectedly reemerged the next day north of the Mascarene Islands. Conditions both conducive and unconducive for tropical cyclone development were present near the embryonic system over the following week. Convective activity increased and decreased diurnally without much persistence. A clearer developmental trend began on 12 March as thunderstorms began to coalesce and persist around a newly formed wind circulation near Tromelin Island; this was designated as Zone of Disturbed Weather 10 by MFR. As convection concentrated further, the system strengthened into a tropical depression and further to a Moderate Tropical Storm on 13 March, receiving the name Herold.

Upon its naming, Herold remained stationary just off the northeastern coast of Madagascar due to its position within a col. Herold gradually intensified in this configuration, developing a large core of strong winds within a favourable environment and later reaching Severe Tropical Storm strength on 14 March. The ocean heat content beneath Herold diminished as the storm remained stationary, resulting in a degradation of the storm's overall convective strength despite the formation of a ragged eye. The weakening of a subtropical ridge over Madagascar imparted an east-southeastward motion on Herold, causing the storm to track over warmer, untapped waters and restrengthen. Accelerating poleward, Herold reached Tropical Cyclone strength on 15 March and briefly attained Intense Tropical Cyclone status on 17 March, peaking with sustained winds of 175 km/h (110 mph). The onset of increasing wind shear and dry air initiated a sustained period of rapid weakening following this peak. Between 17–18 March, the weakening storm's centre tracked 220 km east of Mauritius and 175 km southwest of Rodrigues. On 18 March, Herold's winds fell below Tropical Cyclone strength as wind shear pulled the storm's central circulation and convection apart. MFR issued their last advisory on Herold at 12:00 UTC that day. The storm's remnants continued southeastward, maintaining a region of gale-force winds and an occasional pulse of thunderstorms.

Météo Madagascar issued a green alert for the Antalaha District and Analanjirofo on 13 March following Herold's formation; a yellow alert was later raised for Analanjirofo the following day. The storm produced heavy rains in northeastern Madagascar, affecting over 3,000 people. Sambava recorded 95 mm of rain on 13 March; floods there displaced a hundred people. Rivers near Maroantsetra overflowed and inundated surrounding villages and disrupted traffic, including Andranofotsy in particular. Homes were swept away in Maroantsetra. Floods along the Ankavanana River affected over a thousand people. Overall, flooding impacted 104 schools. Four people were killed in the Sava Region. A class 1 cyclone warning was issued for Mauritius on 15 March, which was upgraded further to a class 2 warning two days later. A class 3 warning was escalated to a class 4 warning for Rodrigues on 18 March. Schools were closed on 17 March on Mauritius and Rodrigues as Herold passed between the islands. Eighty people on Rodrigues sought refuge in eight accommodation centres. The cyclone's effects were ultimately limited to downed trees and power outages in some areas of Rodrigues. A peak gust of 130 km/h was registered at Sir Gaëtan Duval Airport. Herold's distance from the island kept rainfall low, with a maximum of 29 mm in Patate Théophile.

Intense Tropical Cyclone Irondro
On 29 March, monsoonal flow led to the formation of a broad area of low pressure in the central region of the South-West Indian Ocean basin. Showers and thunderstorms began to develop and consolidate in connection with this system south-southwest of Diego Garcia. It was classified by the MFR as a Zone of Disturbed Weather on 31 March and moved slowly during its first two days as an officially designated tropical system. Rainbands took shape around the newly formed center of circulation. Easterly wind shear impinged upon the system during its early stages, but a favorable upper-air environment provided suitable conditions for persistent convection. On 2 April, more favourable conditions for intensification in the wake of a passing equatorial Kelvin wave allowed the storm to a Moderate Tropical Storm; the Mauritius Meteorological Services named it Irondro. Concurrently, the storm began to track towards the southeast in response to a subtropical ridge to its east. Irondro's winds increased throughout the day, particularly following a large burst of thunderstorms around the centre of the storm, reaching Severe Tropical Storm strength by 06:00 UTC on 3 April.

Irondro was upgraded to Tropical Cyclone status at 18:00 UTC on 3 April after developing an intense central dense overcast with some hints of an eye. The development of a pinhole eye and tight rainbands by the end of 3 April indicated rapid intensification was underway. Early on 6 April, Irondro briefly peaked as an Intense Tropical Cyclone with sustained winds of 175 km/h (110 mph). The storm then traversed a region of increasing wind shear, drier air, and diminishing oceanic heat content, precipitating the storm's weakening. The organisation of Irondro's clouds deteriorated throughout 4 April as it was undermined by the steadily increasing wind shear. The next day, the system weakened to a Severe Tropical Storm as the associated convection moved away from the low-level centre of circulation. Its swath of storm-force winds also began to abate along with the fleeting thunderstorm activity. On 6 April, Irondro degenerated into a post-tropical depression and moved into the Australian cyclone region.

Moderate Tropical Storm Jeruto
Late on 13 April, a developing tropical low crossed over the 90th meridian east from the Australian cyclone region. The environment was generally favourable for tropical cyclogenesis, with warm sea surface temperatures, low vertical wind shear and good poleward upper-level outflow. Microwave satellite imagery indicated that formative convective banding had begun to wrap into the centre of circulation, and the JTWC assessed the probability of the system strengthening into a tropical cyclone as medium. However, MFR reported that there was a lack of substantial convergence from the north in the lower troposphere, which they noted could slow or prevent the development of a strong low-level circulation before environmental conditions became less favourable for strengthening.

The system was classified as Tropical Depression 12 by MFR at 06:00 UTC on 14 April, and the JTWC issued a tropical cyclone formation alert a few hours later. Convection increased in organisation throughout the night, and the system was classified as Tropical Storm 26S by the JTWC at 18:00 UTC. It was noted that satellite scatterometer data indicated that the Dvorak technique was underestimating the cyclone's wind speeds at the time. On 15 April, the depression was said to have strengthened into a moderate tropical storm as convection successfully wrapped around the low-level circulation, and it was named Jeruto. Offset by high wind shear, Jeruto began to quickly weaken shortly after being designated as a moderate tropical storm, and was downgraded to a tropical depression just 12 hours after being named as convection quickly became displaced south of the center. Just 6 hours after this downgrade, the JTWC issued its final warning as it became highly disorganized. Jeruto was estimated by MFR to have weakened below tropical depression intensity by early on 16 April, and the last advisory by the MFR on Jeruto was issued on 16 April as it rapidly dissipated.

Tropical Storm Arthur
Tropical Depression One of the 2020 season developed east of Florida around 18:00 UTC on May 16. Six hours later, an Air Force reconnaissance aircraft found that it had attained tropical storm strength. Tropical Storm Arthur weaved along the Gulf Stream and changed little in intensity as it encountered increasing wind shear. After passing east of North Carolina, the system reached peak winds of 60 mph (95 km/h) as deep convection partially covered the center. Shortly after, Arthur interacted with another front and became an extratropical cyclone by 12:00 UTC on May 20. The low turned southeast before dissipating near Bermuda a day later.

Featuring the formation of a pre-season tropical storm, the 2020 Atlantic hurricane season became the record sixth consecutive season with a tropical or subtropical cyclone before the official June 1 start date. Passing within 20 nautical miles of the Outer Banks, Arthur caused tropical storm force wind gusts and a single report of sustained tropical storm force winds at Alligator River Bridge. Arthur caused $112,000 in damage in Florida.

Tropical Storm Bertha
On May 27 a small, well-defined low with centralized convection developed off the coast of South Carolina and the system was classified as a tropical storm. Based on Doppler weather radar and buoy data, the system attained peak winds of 50 mph (85 km/h) shortly before moving inland near Isle of Palms. Turning north and accelerating, the system quickly degraded and transitioned into an extratropical cyclone over Virginia.

Damage was primarily limited to localized flooding, especially around canals, and an EF1 tornado caused minor damage in southern Miami. In coastal South Carolina, there was localized flash flooding, and one person drowned due to rip currents at Myrtle Beach, Overall, Bertha caused at least $133,000 in damage.

Tropical Storm Cristobal
At 10:00 UTC on May 31, Tropical Storm Amanda of the Eastern Pacific basin made landfall on Guatemala and dissipated inland. Its remnants crossed Central America and entered the Bay of Campeche, and at 18:00 UTC on June 1, Tropical Depression Three developed directly from those remnants. By 12:00 UTC the following day, the depression strengthened into Tropical Storm Cristobal. Throughout the remainder of the day, Cristobal's wind field became more symmetrical and well defined and it gradually strengthened with falling barometric pressure as the storm meandered towards the Mexican coastline. Cristobal made landfall as a strong tropical storm just west of Ciudad del Carmen at 13:35 UTC on June 3 at its peak intensity of 60 mph. As Cristobal moved very slowly inland, it weakened back down to tropical depression status as the overall structure of the storm deteriorated. The storm began accelerating northwards on June 5 and by 06:00 UTC that day, despite being situated inland over the Yucatán Peninsula, Cristobal re-intensified back to tropical storm status. As Cristobal moved further north into the Gulf of Mexico, dry air and interaction with an upper-level trough to the east began to strip Cristobal of any central convection, with most of the convection being displaced to the east and north of the center. Late on June 7, Cristobal made landfall over southeastern Louisiana. The system weakened to a tropical depression on the next day, as it moved inland over the state. The storm survived as a tropical depression as it moved up the Mississippi River Valley, before finally becoming extratropical at 00:00 UTC on June 10 over southern Wisconsin. On June 12, Cristobal degenerated into a remnant low, before fully dissipating on June 13.

On June 1, the government of Mexico issued a tropical storm warning from Campeche westward to Puerto de Veracruz. Residents at risk were evacuated. Nine thousand Mexican National Guard members were summoned to aid in preparations and repairs. Significant rain fell across much of Southern Mexico and Central America. Wave heights up to 3 m high closed ports for several days. In El Salvador, a mudslide caused 7 people to go missing. Up to 243 mm of rain fell in the Yucatán Peninsula, flooding sections of a highway. Street flooding occurred as far away as Nicaragua. On June 5, while Cristobal was still a tropical depression, a tropical storm watch was issued from Punta Herrero to Rio Lagartos by the government of Mexico as well as for another area from Intracoastal City, Louisiana to the Florida-Alabama border, issued by the National Weather Service. These areas were later upgraded to warnings and for the Gulf Coast, the warning was extended to the Okaloosa/Walton County line. Heavy rains and damage were reported within the warning areas during Cristobal's passage and the storm caused an estimated US$665 million in damage.

Tropical Storm Dolly
Around June 17, an area of disturbed weather developed just north of the Bahamas after part of a tropical wave and an upper-level trough interacted. The disturbance moved north and organized into a low-pressure area early on June 22. Shortly thereafter, the low became a subtropical depression about 405 mi east-southeast of Cape Cod, Massachusetts. Mid-level dry air and sea surface temperatures that were only marginally favorable resulted in very little strengthening on June 22. However, after moving east-northeastward and away from an upper low, the cyclone developed more deep convection and intensified into Subtropical Storm Dolly by 06:00 UTC on June 23. About six hours later, Dolly transitioned into a tropical cyclone and peaked with sustained winds of 45 mph (75 km/h) and a minimum pressure of 1000 mbar. However, convection rapidly diminished after Dolly moved north of the Gulf Stream and encountered drier air. Early on June 24, Dolly degenerated into a remnant low about 200 mi south of Sable Island. The remnant low continued northeastward and dissipated south of Newfoundland early the next day.

Tropical Storm Edouard
On July 1, a cluster of thunderstorms known as a mesoscale convective vortex formed over the northern Tennessee Valley and slowly moved southeastwards. By July 2, the remnant low emerged off the coast of Georgia, and the NHC began monitoring the low around 00:00 UTC on July 4. Just four hours later, the circulation of the low became better defined and closed, and at 15:00 UTC on July 4 the NHC issued its first advisory on the system as Tropical Depression Five. The system gradually drifted north-northeast towards Bermuda while little change in intensity occurred as the storm passed 70 miles (110 km) north of the island around 09:00 UTC on July 5. By 03:00 UTC on July 6, a large burst of convection as a result of baroclinic forces allowed the depression to strengthen into Tropical Storm Edouard. Edouard further intensified as it began its extratropical transition, reaching peak intensity of 1007 mbar (29.74 inHg) and maximum sustained winds of 45 mph (75 km/h) at 18:00 UTC that same day. Three hours later, it became extratropical while located about 450 miles southeast of Cape Race, Newfoundland.

The Bermuda Weather Service issued a gale warning for the entirety of the island chain in advance of the system on July 4. Unsettled weather later ensued, and the depression caused tropical storm-force wind gusts and moderate rainfall on the island early on July 5. Impacts were relatively minor. Edouard’s remnant brought brief, but heavy, rain to the British Isles, the Netherlands, Germany, southern Denmark and north-west Poland.

Tropical Storm Fay
At 00:00 UTC July 5, shortly after the formation of Tropical Storm Edouard, the NHC began to track an area of disorganized cloudiness and showers in relation to a nearly stationary surface trough in the Gulf of Mexico. The disturbance moved inland in the Florida Panhandle by 12:00 UTC July 6. Two days later, the system re-emerged over the coast of Georgia. Once offshore, the system began to organize as deep convection blossomed over the warm waters of the Gulf Stream. Three hours later, the center reformed near the edge of the primary convective mass, prompting the NHC to initiate advisories on Tropical Storm Fay at 21:00 UTC July 9, located just 40 miles east-northeast of Cape Hatteras. Fay intensified as it moved nearly due north, reaching its peak intensity of 60 mph winds and minimum barometric pressure of 998 mbar. Fay then made landfall east-northeast of Atlantic City, New Jersey at 21:00 UTC July 10 after weakening slightly. It quickly lost intensity inland, and by 06:00 UTC July 11, had weakened to a tropical depression while situated about 50 mi (80 km) north of New York City. The depression transitioned into a post-tropical cyclone three hours later while located roughly 30 mi (45 km) south of Albany, New York.

Immediately upon formation, tropical storm warnings were issued for the coasts of New Jersey, New York, and Connecticut, as the system moved north at 7 mph. Six people were directly killed due to rip currents and storm surge associated with Fay. Overall, damage from the storm on the US Eastern Coast was at least US$350 million, based on wind and storm surge damage on residential, commercial, and industrial properties.

Tropical Storm Gonzalo
Early on July 20, the NHC began monitoring a tropical wave over the central tropical Atlantic for possible development. The wave rapidly organized as it moved quickly westward. By 21:00 UTC July 21, satellite imagery and scatterometer data indicated that the small low pressure system had acquired a well-defined circulation as well as sufficiently organized convection to be designated Tropical Depression Seven. Satellite data received on the morning of July 22, indicated that the tropical depression had strengthened, and at 12:50 UTC, the NHC designated it as Tropical Storm Gonzalo. Gonzalo continued to intensify throughout the day, with an eyewall under a central dense overcast and hints of a developing eye becoming evident. Gonzalo would then reach its peak intensity with wind speeds of 65 mph and a minimum central pressure of 997 mbar at 09:00 UTC the next day. However, strengthening was halted as its central dense overcast was significantly disrupted when the storm entrained very dry air into its circulation from the Saharan Air Layer to its north. Convection soon redeveloped over Gonzalo's center as the system attempted to mix out the dry air from its circulation, but the tropical storm did not strengthen further due to the hostile conditions. After making landfall on the island of Trinidad as a weak tropical storm, Gonzalo weakened to a tropical depression at 18:00 UTC on July 25. Three hours later, Gonzalo opened up into a tropical wave as it made landfall in northern Venezuela.

On July 23, hurricane watches were issued for Barbados, St Vincent and the Grenadines, and a tropical storm watch was issued later that day for Grenada and Tobago. After Gonzalo failed to strengthen into a hurricane on July 24, the hurricane and tropical storm watches were replaced with tropical storm warnings. Tropical Storm Gonzalo brought squally weather to Trinidad and Tobago and parts of southern Grenada and northern Venezuela on July 25. However, the storm's impact ended up being significantly smaller than originally anticipated. The Tobago Emergency Management Agency only received two reports of damage on the island: a fallen tree on a health facility in Les Coteaux and a damaged bus stop roof in Argyle.

Hurricane Hanna
At 06:00 UTC July 19, the NHC noted a tropical wave over eastern Hispaniola and the nearby waters for possible development. In the Gulf of Mexico, where conditions were more favorable for development, the system began to steadily organize as a broad low pressure area formed within it. Surface observations along with data from an Air Force Hurricane Hunter Aircraft showed that the area of low pressure developed a closed circulation along with a well-defined center, prompting the NHC to issue its first advisory on Tropical Depression Eight at 03:00 UTC on July 23. The depression continued to become better organized in the gulf and was designated Tropical Storm Hanna at 03:00 UTC on July 24, while located about 385 miles east-southeast of Corpus Christi, Texas. Over the ensuing 24 hours, Hanna underwent rapid intensification as its inner core and convection became better organized. By 12:00 UTC July 25, radar and data from another Hurricane Hunter Aircraft showed that Hanna had intensified into the first hurricane of the season. Hanna continued to strengthen further, reaching its peak intensity with 90 mph winds by 21:00 UTC on July 25, before making landfall an hour later at Padre Island, Texas. After making a second landfall in Kenedy County, Texas at the same intensity at 23:15 UTC, the system then began to rapidly weaken, dropping to tropical depression status at 22:15 UTC the next day after crossing into Northeastern Mexico.

Immediately after the system was classified as a tropical depression, tropical storm watches were issued for much of the Texas shoreline. At 21:00 UTC on July 24, a hurricane warning was issued from Baffin Bay to Mesquite Bay, Texas, due to Hanna being forecast to become a hurricane before landfall. As the hurricane approached landfall, local officials underscored the reality of the COVID-19 pandemic when warning residents living in flood-prone neighborhoods about the prospect of evacuation. Texas governor Greg Abbott announced the deployment of 17 COVID-19 mobile testing teams focused on shelters and 100 medical personnel provided by the Texas National Guard. The precursor disturbance to Hanna dropped heavy rain to parts of Hispaniola, the Florida Keys and Cuba. In Pensacola, Florida, a 33-year-old police deputy was drowned by rip currents while trying to save his 10-year-old son in Sandestin Beach. In portions of Louisiana, Mississippi, Alabama, and the Florida Panhandle, the outer bands of Hanna brought heavy rainfall, even threatening street flooding in New Orleans. Hanna brought storm surge flooding, destructive winds, torrential rainfall, flash flooding and isolated tornadoes across South Texas and Northeastern Mexico. Flooding in the later region caused four fatalities.

Hurricane Isaias
The National Hurricane Center first began tracking a vigorous tropical wave off the coast of Africa on July 23. The wave gradually organized and became better defined, developing a broad area of low pressure. The system moved just south of Dominica, and at 03:00 UTC on July 30, it organized into a tropical depression. Due to its precursor disturbance already having gale-force winds, it was immediately declared a tropical storm and given the name "Isaias". The following day, Isaias passed south of Puerto Rico and made landfall on the Dominican Republic. At 03:40 UTC on July 31, Isaias strengthened into a hurricane as it pulled away from the Greater Antilles. The storm fluctuated in intensity afterwards, due to strong wind shear and dry air, with its winds peaking at 85 mph and its central pressure falling to 987 mbar. At 15:00 UTC on August 1, Isaias made landfall on North Andros, Bahamas with winds around 80 mph, and the system weakened to a tropical storm at 21:00 UTC. It then turned north-northwest, paralleling the east coast of Florida and Georgia while fluctuating between 65 - 70 mph wind speeds. As the storm accelerated northeastward and approached the Carolina coastline, wind shear relaxed, allowing the storm to quickly intensify back into a hurricane at 00:00 UTC on August 4, and at 03:10 UTC, Isaias made landfall on Ocean Isle Beach, North Carolina, with 1-minute sustained winds of 85 mph. Following landfall, Isaias accelerated and only weakened slowly, dropping below hurricane status at 07:00 UTC over North Carolina. The storm passed over the Mid-Atlantic states and New England before transitioning into an extratropical cyclone near the American-Canadian border, and subsequently weakening progressing into Quebec.

Numerous tropical storm watches and warnings as well as hurricane watches and hurricane warnings were issued for the Lesser Antilles, Greater Antilles, Bahamas, Cuba, and the entire East Coast of the United States. Isaias caused devastating flooding and wind damage in Puerto Rico and the Dominican Republic. Several towns were left without electricity and drinking water in Puerto Rico. Two people were killed in Puerto Rico, and a person was killed the Dominican Republic. In the United States, Isaias triggered a large tornado outbreak that prompted the issuance of 109 tornado warnings across 12 states. A total of 39 tornadoes touched down, the strongest being an EF3 tornado that struck a mobile home park near Windsor, North Carolina on August 4. Fifteen people were killed in the United States. Damage estimates exceeded US$4.725 billion, making Isaias the costliest tropical cyclone to strike the Northeastern U.S. since Hurricane Sandy in 2012.

Tropical Depression Ten
On July 28, a tropical wave emerged off the west coast of Africa. Slow-moving, the system soon developed a defined low on July 29 as it turned north along the east side of an upper-level low. Associated convection became sufficiently organized for the system to be classified as a tropical depression the following day; at this time the cyclone was located about 230 mi east-southeast of the easternmost Cabo Verde Islands. The system reached its peak intensity with winds of 35 mph (55 km/h) and a pressure of 1008 mbar around 00:00 UTC on August 1. Scatterometer data revealed conflicting data, with tropical storm-force winds noted in one pass within the deepest convection to the southwest of the storm's center where the weakest winds are typically found. A near-concurrent pass from another satellite showed lower winds, and given the conflicting data the NHC determined the system to have not become a tropical storm. Thereafter, a combination of decreasing sea surface temperatures and dry air caused convection to dissipate. The depression turned west-northwest and degraded into a remnant low later that day. It soon dissipated on August 2 north of the Cabo Verde Islands.

Tropical Storm Josephine
On August 7, the NHC began monitoring a tropical wave over the tropical Atlantic. The wave's circulation slowly became more defined over the ensuing several days, with signs of convective organization becoming evident on satellite imagery on the morning of August 11. The system's circulation grew increasingly better organized during the day, and at 21:00 UTC was designated Tropical Depression Eleven. The depression's ability to intensify was initially hindered by dry air and wind shear. After two days with little change in intensity, convection began to form closer to the estimated center of the depression, and as a result it intensified into Tropical Storm Josephine at 15:00 UTC, August 13. Josephine's intensity began to fluctuate on August 14, as wind-shear affected the system, causing convection to be displaced from the circulation. Hurricane Hunter aircraft investigated the system later that day and found that the storm's center had relocated further north in the afternoon hours. Nonetheless, Josephine headed into increasingly hostile conditions as it began to pass north of the Leeward Islands. As a result, the storm later weakened, becoming a tropical depression early on August 16, just north of the Virgin Islands. The weakening cyclone's circulation became increasingly ill-defined, and Josephine eventually weakened into a trough of low pressure later that day.

Tropical Storm Kyle
On August 13, the NHC began to track an area of low pressure located over eastern North Carolina. As it moved over the Outer Banks and then offshore overnight, warm water temperatures in the Atlantic allowed the system to rapidly organize, and at 21:00 UTC on August 14, the NHC designated the system as Tropical Storm Kyle. The storm proceeded to move quickly east-northeastward along the Gulf Stream, and reaching its peak intensity with maximum sustained winds of 50 mph and a minimum pressure of 1000 mb by mid-day on August 15. Meanwhile, its circulation quickly started to become elongated as a consequence of strong upper-level westerly winds. As a result, Kyle began to lose its tropical characteristics over the ensuing hours with its circulation becoming asymmetric, ultimately leading to its becoming a post-tropical cyclone early on August 16 and dissipating by the following morning. Kyle's remnant energy was later absorbed by extratropical Storm Ellen, a European windstorm which brought hurricane-strength winds to the Republic of Ireland and the United Kingdom.

Hurricane Laura
On August 16, the National Hurricane Center (NHC) began tracking a large tropical wave that had emerged off the West African coast, and was traversing across the Intertropical Convergence Zone toward the Windward Islands. As the system moved across the central tropical Atlantic toward the Windward Islands, satellite imagery revealed that the system had developed a well-defined center of circulation with sufficient organized deep convection to be classified as a tropical depression at 03:00 UTC on August 20. The next day at 13:05 UTC, NOAA Hurricane Hunter Aircraft found that the depression had strengthened and become Tropical Storm Laura. It remained quite disorganized, however, and the system was unable to strengthen further, due to moderate wind shear. The storm then moved over the northern Leeward islands, and it then strengthened as it approached Puerto Rico. Early on August 23, Laura made landfall near San Pedro de Macorís, Dominican Republic, with 45 mph (75 km/h) winds. Laura retained large amounts of convection despite interaction with the mountainous terrain of Hispaniola, and gained renewed strength later that day once back over water, moving between Haiti and eastern Cuba. Early on August 25, the storm entered the Gulf of Mexico and became a Category 1 hurricane at 12:15 UTC on the same day. Afterward, it rapidly intensified into a major hurricane, with its sustained wind speeds increasing by 50 mph during the 24 hours ending at 15:00 UTC on August 26, reaching 125 mph (200 km/h). Later that day, at 18:00 UTC, it attained Category 4 status, and then, at 02:00 UTC on August 27, Laura reached its peak intensity with 1-minute sustained winds at 150 mph (240 km/h) and a minimum central pressure of 937 mbar (27.67 inHg). At 06:00 UTC, Laura made landfall near Cameron, Louisiana, with sustained winds of 150 mph (240 km/h), making it the strongest Louisiana-landfalling hurricane in terms of wind speed since the 1856 Last Island hurricane. Laura steadily weakened after moving inland, dropping to tropical storm strength roughly 11 hours later over Northern Louisiana, and then to a tropical depression over Arkansas early on August 28. The deteriorating system turned northeastward, and by 09:00 UTC on August 29, degenerated into a remnant low over north central Kentucky.

As Laura passed through the Northern Leeward Islands, it brought heavy rainfall to the islands of Guadeloupe and Dominica, and prompted the closing of all ports in the British Virgin Islands. The storm produced heavy downpours upon Puerto Rico and Hispaniola. Laura pummeled southwestern Louisiana and southeastern Texas, with Lake Charles, Louisiana being particularly hard hit. Altogether, there were 77 storm related deaths: four in the Dominican Republic, 31 in Haiti, and 42 in the United States.

Hurricane Marco
The NHC began to track a tropical wave located over the central tropical Atlantic at 00:00 UTC on August 16. Initially hindered by its speed and unfavorable conditions in the eastern Caribbean, the wave began organizing once it reached the central Caribbean on August 19. At 15:00 UTC on August 20, the NHC designated the wave as Tropical Depression Fourteen. Intensification was initially slow, but the depression strengthened into Tropical Storm Marco at 03:00 UTC on August 22. Marco passed just offshore of Honduras and, as a result of favorable atmospheric conditions, quickly intensified to an initial peak of 65 mph and a pressure of 992 mb, with a characteristic eye beginning to form on radar. After a Hurricane Hunters flight found evidence of sustained winds above hurricane force, Marco was upgraded to a Category 1 hurricane at 16:30 UTC on August 23. Even so, strong southwesterly wind shear soon displaced the storm's convection, exposing its low-level center, which caused the system to weaken. It was downgraded to a tropical storm at 03:00 UTC on October 24. Later that day, at 23:00 UTC, Marco made landfall near the mouth of the Mississippi River as a weak tropical storm with winds at 40 mph and a pressure of 1006 mb. Marco degenerated into a remnant low just south of Louisiana at 09:00 UTC on August 25.

Marco was indirectly responsible for the death of one person in Chiapas, Mexico. As the storm ultimately weakened faster than anticipated, its landfall in Louisiana was much less damaging than initially feared, only causing around $35 million in damage.

Tropical Storm Omar
During the last few days of August, a cold front spawned a trough over Northern Florida, and eventually, a low-pressure area formed offshore of the southeast coast of the United States. The low rapidly organized as it drifted on top of the Gulf Stream, and was classified as Tropical Depression Fifteen at 21:00 UTC on August 31. Moving generally northeastward away from North Carolina, the depression struggled to intensify in a marginally favorable environment with warm Gulf Stream waters being offset by high wind shear. Eventually, satellite estimates revealed that the depression was intensifying. The system became consolidated enough to be upgraded to a tropical storm, and was thus given the name Omar at 21:00 UTC on September 1. After being hit by 40-50 knots of northwesterly wind shear during the morning of September 2, Omar weakened back to a tropical depression later in the day, when it was roughly 265 mi (430 km) north of Bermuda due to the high wind shear. Early on September 5, the center began to fully separate from the bursts of convection, and by 21:00 UTC that day, Omar degenerated into a remnant low.

Hurricane Nana
On August 27, the NHC began to monitor a tropical wave that was moving westward over the Atlantic. Over the next four days, system gradually organized and acquired gale-force winds and at 06:00 UTC on September 1, it developed into a tropical storm. Operationally, it was not named until 16:00 UTC, when a hurricane hunter aircraft investigating the storm found a well-defined low-level circulation (LLC), allowing the NHC to name the system Nana. By 18:00 UTC that same day, the storm strengthened some more, obtaining 1-minute sustained winds of 60 mph (95 km/h). Afterward, moderate northerly shear of 15 knots halted the trend and partially exposed the center of circulation, although its pressure continued to drop. After the shear abated some late on September 2, Nana redeveloped convection over its center and quickly intensifed into a hurricane at 03:00 UTC on September 3, reaching its peak intensity with 1-minute sustained winds of 75 mph (120 km/h) and a minimum central pressure of 994 mbars (29.36 inHg). Three hours later, Nana made landfall between Dangriga and Placencia in Belize at peak intensity. Nana quickly weakened, falling to a tropical depression at 18:00 UTC. It degenerated into a remnant low at 00:00 UTC on September 4 before dissipating shortly thereafter. Its mid-level remnants eventually spawned Tropical Storm Julio in the eastern Pacific on September 5.

Nana caused street flooding in the Bay Islands of Honduras. Hundreds of acres of banana and plantation crops were destroyed in Belize, where a peak wind speed of 61 mph (98 km/h) was reported at a weather station in Carrie Bow Cay. Total economic losses in Belize exceeded $20 million. Heavy amounts of precipitation also occurred in northern Guatemala.

Hurricane Paulette
The NHC began to track a tropical wave located over Africa on August 30. The wave became better organized and formed an area of low pressure on September 6, while midway between the west coast of Africa and the Leeward Islands, but convective activity remained disorganized. In the early hours of September 7, the wave became more organized, and the NHC began issuing advisories for Tropical Depression Seventeen at 03:00 UTC on September 7. At 15:00 UTC the same day, the NHC upgraded the system to Tropical Storm Paulette. The storm moved generally west-northwestward over the central tropical Atlantic as it gradually intensified. At 15:00 UTC on September 8, Paulette reached its first peak intensity with 1-minute sustained winds of 65 mph (100 km/h) with a minimum central pressure of 995 mbar (29.39 inHg). Twelve hours later, an increase in wind shear weakened the storm. On September 11, despite a very harsh environment, Paulette began to re-intensify. The shear later began to lessen, allowing Paulette to become more organized and begin to form an eye, becoming a hurricane at 03:00 UTC on September 13. Dry air entrainment gave the storm a somewhat ragged appearance, but it continued to slowly strengthen as it approached Bermuda with its eye clearing out and its convection becoming more symmetric. Paulette then made a sharp turn to the north and made landfall in northeastern Bermuda at 09:00 UTC on September 14 with 90 mph (150 km/h) winds and a 973 mb (28.74 inHg) pressure. The storm then strengthened into a Category 2 hurricane as it accelerated northeast away from the island on September 14, reaching its peak intensify of 105 mph (170 km/h) and a pressure of 965 mb (28.50 inHg) later that day. As Paulette accelerated northeastward, it began to start extratropical transition on September 15, which it completed the next day.

After about five days of slow southward movement, the extratropical cyclone began to redevelop a warm core and its wind field shrank considerably. By September 22, it had redeveloped tropical characteristics and the NHC resumed issuing advisories shortly thereafter. It moved eastward over the next day, and became post-tropical for the second time in its lifespan early on September 23 and subsequently dissipated.

Trees and power lines were downed throughout Bermuda, leading to an island-wide power outage. In Lavallette, New Jersey, a 60-year-old man drowned while swimming after being caught in rough surf produced by Paulette.

Tropical Storm Rene
A tropical wave emerged into the Atlantic on September 6. A well-defined low-pressure area already existed along the way, though convection initially remained limited. After a burst in deep convection the wave was designated as a tropical depression at 06:00 UTC on September 7 approximately 200 mi east of the easternmost islands of Cabo Verde. Convection consolidated and organized further, with banding developing later that day, while the depression intensified into Tropical Storm Rene about 12 hours later. Moving west-northwestward for much of its duration, Rene made landfall on Boa Vista Island around 00:00 UTC on September 8 with sustained winds of 40 mph (65 km/h). Dry air and only marginally warm seas caused convection to wane and Rene weakened to a tropical depression several hours later. After another burst in deep convection early on September 9, the cyclone re-strengthened into a tropical storm. At 12:00 UTC on September 10, Rene peaked with sustained winds of 45 mph (75 km/h) and a minimum barometric pressure of 1001 mbar. Showers and thunderstorms decreased starting on the following day due to dry air and Rene weakened to a tropical depression on September 12. Strong westerly shear caused further weakening, with Rene degenerating into a trough about 1035 mi northeast of the Leeward Islands. The remnants turned southwestward and dissipated a few days later.

A tropical storm warning was issued for the Cabo Verde Islands when advisories were first issued on the storm at 09:00 UTC on September 7. Rene produced gusty winds and heavy rains across the islands, but no serious damage was reported. The warning was discontinued at 21:00 UTC on September 8.

Hurricane Sally
On September 10, the NHC began to monitor an area of disturbed weather over The Bahamas for possible development. Over the next day, convection rapidly increased, became better organized, and formed a broad area of low-pressure on September 11. At 21:00 UTC, the system had organized enough to be designated as Tropical Depression Nineteen. At 06:00 UTC on September 12, the depression crossed the Florida coast just south of Miami, with winds of 35 mph (55 km/h) and a pressure of 1007 mbar (29.74 inHg). Shortly after moving into the Gulf of Mexico, the system strengthened into Tropical Storm Sally at 18:00 UTC the same day. Northwesterly shear caused by an upper-level low caused the system to have a sheared appearance, but it continued to strengthen as it gradually moved north-northwestward. Sally began to go through a period of rapid intensification around midday on September 14. Its center reformed under a large burst of deep convection and it strengthened from a 65 mph (105 km/h) tropical storm to a 90 mph (140 km/h) Category 1 hurricane in just one and a half hours. It continued to gain strength and became a Category 2 hurricane later that evening. However, upwelling due to its slow movement as well increasing wind shear weakened Sally back down to Category 1 strength early the next day. It continued to steadily weaken as it moved extremely slowly northwest then north, although its pressure continued to fall. However, as Sally approached the coast, its eye quickly became better defined and it abruptly began to re-intensify. By 05:00 UTC on September 15, it had become a Category 2 hurricane again. At around 09:45 UTC, the system made landfall at peak intensity near Gulf Shores, Alabama with winds of 105 mph (165 km/h) and a pressure of 965 mbars (28.50 inHg). The storm rapidly weakened as it moved slowly inland, weakening to a Category 1 hurricane at 13:00 UTC and to a tropical storm at 18:00 UTC. It further weakened to a tropical depression at 03:00 UTC on September 17, before degenerating into a remnant low at 15:00 UTC.

A tropical storm watch was issued for the Miami metropolitan area when the storm first formed, while numerous watches and warnings were issued as Sally approached the U.S. Gulf Coast. Several coastline counties and parishes on the Gulf Coast were evacuated. In South Florida, heavy rain led to localized flash flooding, while the rest of peninsula saw continuous shower and thunderstorm activity due to asymmetric structure of Sally. The area between Mobile, Alabama and Pensacola, Florida took the brunt of the storm with widespread wind damage, storm surge and flooding, and over 2 ft (61 cm) of rainfall was recorded near Naval Air Station Pensacola. several tornadoes touched down in the region as well. Ultimately, eight people were killed and damage estimates were at least $6.25 billion.

Hurricane Teddy
The NHC began to monitor a tropical wave over Africa early on September 7. By the afternoon of September 12, the disturbance, then located several hundred miles west-southwest of the Cabo Verde Islands, had become better defined, and at 21:00 UTC that night, the NHC designated it as Tropical Depression Twenty. After overcoming persistent northerly shear, the system became better organized and strengthened into Tropical Storm Teddy at 09:00 UTC on September 14. The storm continued to intensify, with an eye beginning to form late on September 15. Satellite data received shortly after 06:00 UTC the following day indicated that Teddy had quickly intensified into an 85 mph (140 km/h) hurricane. The storm continued to intensify, becoming a Category 2 hurricane later that day. However, some slight westerly wind shear briefly halted intensification and briefly weakened the storm to a Category 1 at 03:00 UTC on September 17. When the shear decreased, Teddy rapidly re-intensified into a major hurricane at 15:00 UTC that day. Teddy further strengthened into a Category 4 hurricane six hours later, reaching its peak intensity of 140 mph (220 km/h) and a pressure of 945 mb (27.91 inHg). Internal fluctuation and an eyewall replacement cycle caused the storm to weaken slightly to a Category 3 hurricane at 09:00 UTC on September 18. Soon after, Teddy briefly re-strengthened into a Category 4 hurricane before another eyewall replacement cycle weakened it again to Category 3 intensity. On the morning of September 20, the hurricane's internal structure deteriorated substantially, causing its eye to nearly dissipate, and by 12:00 UTC Teddy had weakened to Category 2 intensity.

While moving generally in a north-northeasterly direction across the central Atlantic, Teddy weakened to a Category 1 hurricane during the afternoon of September 21. Later that day, the system began to merge with a mid-latitude trough; the infusion of energy from the trough in combination with the warm waters of the Gulf Stream caused it to re-intensify to Category 2 hurricane late that night. As Teddy began to undergo an extratropical transition on September 22, while moving toward Nova Scotia, its windfield expanded greatly, with hurricane-force winds extending outward up to 150 mi (240 km) from the center and tropical-storm-force winds extending outward up to 550 mi (890 km). Later that same day, the hurricane weakened to Category 1 intensity, before becoming a strong post-tropical cyclone at around 00:00 UTC on September 23. The cyclone made landfall approximately 12 hours later near Ecum Secum, Nova Scotia with maximum sustained winds near 65 mph (100 km/h). The storm then made landfall in Newfoundland as a weakening extratropical storm.

Hurricane Teddy generated large ocean swells which spread along much of the U.S. Atlantic coast and from the northern Caribbean to Bermuda. Two people drowned in the waters off La Pocita in Loíza, Puerto Rico due to rip currents generated by these swells on September 18, as did a swimmer at Point Pleasant Beach, New Jersey on September 23.

Tropical Storm Vicky
In the early hours of September 11, a tropical wave moved off the coast of Africa. The disturbance steadily organized, and the NHC issued a special advisory to designate the system as Tropical Depression Twenty-One at 10:00 UTC on September 14. The depression strengthened into Tropical Storm Vicky five hours later based on scatterometer data. Despite extremely strong shear partially caused by Hurricane Teddy's outflow removing all but a small convective cluster to the northeast of its center, Vicky intensified further, reaching its peak intensity with 1-minute sustained winds of 50 mph (85 km/h) and a pressure of 1000 mbar (29.53 inHg) at 03:00 UTC on September 15. Eventually, 50 knots of wind shear began to take its toll on Vicky, and its wind speed began to fall. It weakened into a tropical depression at 15:00 UTC on September 17, and degenerating into a remnant low six hours later. The low continued westward producing weak disorganized convection before opening up into a trough late on September 19 and dissipating the next day.

The tropical wave that spawned Tropical Storm Vicky produced flooding in the Cabo Verde Islands. The floods killed one person in Praia on September 12.

Tropical Storm Beta
On September 10, the NHC began to monitor a trough of low pressure that had formed over the northeastern Gulf of Mexico. Development of the system was not expected at the time due to strong upper-level winds produced by Hurricane Sally. The disturbance nonetheless persisted, moving southwestward into the southwestern Gulf of Mexico where it began to organize as Sally moved away into the Southeastern United States early on September 16. The next day, hurricane hunters found a closed circulation, and as thunderstorms persisted near the center, the NHC initiated advisories on Tropical Depression Twenty-Two at 23:00 UTC on September 17. At 21:00 UTC on September 18, the system strengthened into Tropical Storm Beta. Although affected by wind shear and dry air, the storm continued to intensify, reaching a peak intensity of 60 mph (95 km/h) and a pressure of 994 mbar|mb (29.36 inHg) at 15:00 UTC on September 19, with a brief mid-level eye feature visible on radar imagery. However, it became nearly stationary after turning westward over the Gulf of Mexico, causing upwelling and weakening the storm. Beta continued to weaken, and made landfall on the Matagorda Peninsula in Texas at 04:00 UTC on September 22, with winds of 45 mph (75 km/h). Afterwards, Beta fell to tropical depression status at 15:00 UTC. It then became nearly stationary again before turning east, with the NHC issuing their final advisory and giving future advisory responsibilities to the Weather Prediction Center (WPC). It transitioned to a remnant low at 03:00 UTC on September 23.

Beta caused extensive flooding throughout much of the Greater Houston metropolitan area. Houston officials reported that over 100,000 gallons of domestic wastewater spilled at five locations in the city as a result; officials also reported that one man drowned in Brays Bayou.

Tropical Storm Wilfred
On September 13, the NHC began to monitor a tropical wave over West Africa for possible development. The wave subsequently emerged over the eastern Atlantic and began to slowly organize as it moved westward, and, though it had not yet obtained a well-defined low-level circulation (LLC), it was producing winds near tropical-storm-force by late September 17. Later, at 15:00 UTC on September 18, an LLC was found and, as the system already had gale-force winds, was designated Tropical Storm Wilfred. Located at a relatively low latitude, Wilfred remained weak and changed little in appearance due to wind shear and unfavorable conditions caused by the outflow of the nearby Hurricane Teddy. As a result, Wilfred failed to strengthen further, subsequently weakening to a tropical depression at 15:00 UTC on September 20. Soon, Wilfred's convection became more linear and may have possibly be forced by the upper-level trough. Wilfred eventually degenerated into a trough at 03:00 UTC on September 21.

Subtropical Storm Alpha
At 06:00 UTC on September 15, the NHC, together with Météo France, began tracking a non-tropical low pressure area north of 45°N, a few hundred miles north of the Azores. It was given a low chance of development as it moved southeast. Over the next few days, it organized while the extratropical system surrounding it gradually weakened, although its proximity and fast movement towards the coast caused the NHC to lower its odds of development. Early on September 18, the system started to rapidly become better defined and the NHC designated it as Subtropical Storm Alpha at 16:30 UTC. Alpha made landfall just north of Lisbon, Portugal, at 18:30 UTC. After landfall, the storm rapidly weakened, becoming a remnant low over the district of Viseu in Portugal at 03:00 UTC on September 19.

In preparation for Alpha on September 18, orange warnings were raised for high wind and heavy rain in Coimbra District and Leiria District of Portugal. Alpha and its associated low produced extensive wind damage, spawned at least two tornadoes, and caused extreme street flooding. In Spain, the front associated with Alpha caused a train to derail in Madrid (no one was seriously injured), while lightning storms on Ons Island caused a forest fire. A woman died in Calzadilla after a roof collapsed.

Tropical Storm Gamma
The NHC initiated advisories on Tropical Depression Twenty-Five at 15:00 UTC on October 2. Eight hours later, the depression developed into Tropical Storm Gamma, while located off the eastern coast of Mexico's Yucatán Peninsula. Gamma began to quickly intensify after formation, almost reaching hurricane strength at 15:00 UTC on October 3. Shortly thereafter, at around 16:45 UTC, Gamma made landfall near Tulum, Quintana Roo, at peak strength with winds of 70 mph (110 km/h) and a pressure of 980 mb. Gamma weakened some as it passed over the northern Yucatán, then emerged over the southern Gulf of Mexico early on October 4, with maximum sustained winds of 50 mph (95 km/h). Gamma re-intensified slightly after moving back over water, but stalled during the afternoon, before increased wind shear left the center exposed, causing it to weaken to a tropical depression by 21:00 UTC on October 5. The storm became post tropical six hours later just 85 miles north of the Yucatán Peninsula as it failed to redevelop any central convection.

Numerous tropical cyclone watches and warnings were issued for parts of the Yucatán Peninsula in Mexico following the formation of Gamma and thousands of people were evacuated. Gamma produced strong winds, heavy rainfall, flash flooding, landslides, and mudslides in the region. At least seven fatalities have been confirmed.

Hurricane Delta
On October 1, the NHC began to monitor a tropical wave located a few hundred miles east of the Lesser Antilles for potential development. Later, at 21:00 UTC on October 4, the system was classified as Potential Tropical Cyclone Twenty-Six. By 03:00 UTC on October 5, it had become sufficiently organized to be labeled a tropical depression. The system continued to gain strength and at 12:00 UTC it was designated Tropical Storm Delta, while located roughly 100 mi south of Jamaica. Delta soon began to rapidly intensify, attaining hurricane strength 12 hours later. By 15:20 UTC on October 6, a Hurricane Hunters reconnaissance aircraft found that the system had continued to rapidly intensify into a Category 4 major hurricane with maximum sustained winds near 130 mph. Delta's breakneck rate of intensification was due to a combination of extremely warm ocean water temperatures, low wind shear and sufficiently moist air aloft. After attaining maximum sustained winds of 145 mph (230 km/h) and a pressure of 956 mb (28.23 inHg), Delta weakened early on October 7 due to a slight increase in mid-level wind shear, which inhibited upper-level outflow from the storm and disrupted its small core. Later that day, around 10:30 UTC, it made landfall near Puerto Morelos, Quintana Roo as a Category 2 hurricane with wind speeds of 110 mph (175 km/h). Delta spent several hours over land before emerging off the coast of the Yucatán Peninsula and into the Gulf of Mexico north of Dzilam de Bravo, Yucatán, as a Category 1 hurricane around 21:00 UTC. It regained Category 2 status early on October 8, and strengthened back into a major hurricane later that day. At 09:00 UTC on October 9, Delta reached its lowest central pressure of 953 mb (28.14 inHg) and secondary peak sustained winds of 120 mph (195 km/h). Delta weakened on October 9 to category 2 strength as it moved toward the southwestern Louisiana coast, and made landfall near Creole, Louisiana with winds of 100 mph (155 km/h) at 23:00 UTC. By 06:00 UTC on October 10, Delta had weakened to a tropical storm, and by 15:00 UTC to a tropical depression. It became post-tropical six hours later while located about 80 mi (130 km) west-southwest of Tupelo, Mississippi.

As Delta was nearing landfall in Quintana Roo, Mexican president Andrés Manuel López Obrador announced on October 6 the activation of the DN-III emergency plan and the mobilization of 5,000 soldiers of the Mexican Armed Forces to help with the evacuation of sheltering people in the region. There were no immediate reports of deaths or injuries, but there were numerous reports of fallen trees and damage to the region's electrical grids. As Delta moved into the northern Gulf of Mexico, widespread watches and warnings were issued along the U.S. Gulf Coast. States of emergency were declared in Louisiana, Mississippi, and Alabama and numerous coastal, low-lying, and flood prone areas were evacuated. The hurricane and its remnants produced heavy rain, strong winds, storm surge, and tornadoes across much of the Southeastern United States. Altogether, there were six storm-related fatalities, two each in: Yucatán, Louisiana and Florida.

Hurricane Epsilon
The NHC started monitoring a non-tropical low late on October 15. It slowly organized and gained convection as it meandered southeast of Bermuda. Early on October 19, the NHC issued a special advisory on the system as it became more well-defined, dubbing it Tropical Depression Twenty-Seven as it became nearly stationary. Three hours later, the system strengthened into Tropical Storm Epsilon, and then gradually intensified the following day as it completed a small counter-clockwise loop. An eye soon became apparent on infrared satellite images, and Epsilon strengthened into a hurricane at 03:00 UTC on October 21. At 21:00 UTC that day, a NOAA hurricane hunter aircraft reported that the storm had rapidly strengthened to a Category 3 hurricane, becoming the fourth major hurricane of the season. Epsilon reached its peak intensity of 115 mph (185 km/h) and pressure of 951 mbar (28.08 inHg) three hours later. Its unusual rapid intensification over cool sea surface temperatures and moderate wind shear was unprecedented by forecasters and was also the farthest east any tropical cyclone had rapidly intensified this late in the Atlantic hurricane season. By 09:00 UTC on October 22 the storm started to weaken with the eye becoming increasingly cloud-filled, and Epsilon was downgraded to a Category 2 hurricane. The eye began to re-emerge later in the day though reconnaissance aircraft found the storm had weakened to a Category 1 hurricane at 15:00 UTC. That night, Epsilon made its closest advance toward Bermuda, passing about 190 mi to its east. Epsilon continued to weaken very slowly as it moved northward toward the north extent of the Gulf Stream and encountered colder sea surface temperatures. By the morning of October 25, its wind field was beginning to grow again as the hurricane began its extratropical transition; although it continued to produce inner-core convection. Epsilon dropped below hurricane intensity at 21:00 UTC that evening, and completed its post-tropical transition by 03:00 UTC on October 26. The remnants of Epsilon were later absorbed into a deep extratropical area of low pressure southwest of Iceland. The trailing weather fronts associated with this low produced waves up to 98 ft on the coast of Ireland on October 28. In advance, Met Éireann issued yellow warnings for wind for the counties of Cork, Wexford, and Waterford, and the Met Office issued the same for parts of Wales and North West England.

The hurricane's large wind field prompted the issuance of a tropical storm watch for Bermuda at 15:00 UTC on October 20, which was later upgraded to a warning 24 hours later. Although the Bermuda Weather Service anticipated that hurricane-force winds would not impact the island, the Government of Bermuda warned residents to prepare for power outages and to check their emergency supplies. Additionally, Dangerous Surf Advisory signs were posted at south shore beaches. Rainfall on the island as the storm passed by amounted to less than an inch; winds at Bermuda's airport gusted near tropical storm-force, with a peak wind gust of 38 mph. The hurricane also generated large sea swells from Bermuda to the Bahamas, the Greater Antilles and the Leeward Islands. As Epsilon began moving away from Bermuda on October 23, the tropical storm warning was cancelled.

Hurricane Zeta
On 21:00 UTC on October 24, a system had organized enough to be designated as Tropical Depression Twenty-Eight. At 06:00 UTC the following morning, the depression strengthened into Tropical Storm Zeta, Despite experiencing some north-northwestwardly shear, Zeta steadily intensified, and reached hurricane strength by 19:20 UTC on October 26. It made landfall north of Tulum, Quintana Roo at 04:00 UTC the next day with winds of 80 mph (130 km/h) and a pressure of 977 mbars (28.85 inHg). The hurricane weakened to a tropical storm while inland at 09:00 UTC. Dry air wrapped around the northern half of Zeta's circulation as it moved off shore into the Gulf of Mexico, leaving the center partially exposed, though it becoming better organized late on October 27, with a ragged eye feature and deep convection and visible. At 06:00 UTC, Zeta became a hurricane again as it began another rapid intensification phase. Zeta continued to strengthen until it reached its peak intensity of 110 mph (175 km/h) and a minimum pressure of 970 mbar as it made landfall in Cocodrie, Louisiana at 21:00 UTC. Zeta steadily weakened after landfall, falling to tropical storm status over central Alabama at 06:00 UTC on October 29, before transitioning into a post-tropical cyclone over central Virginia 12 hours later. The remnants of Zeta then moved quickly out over the Atlantic.

Heavy rain in Jamaica caused a landslide that killed two persons. Strong winds and rain caused flooding and damaged infrastructure in Mexico's Yucatán Peninsula. There were six storm related deaths in the United States: Alabama, Louisiana and Mississippi each had one death; three people were killed in Georgia. Zeta flooded city streets and knocked out power to more than 2.6 million homes and businesses across the Southeastern United States; it also disrupted 2020 election early voting in several states. As the remnants of Zeta moved off shore from the continental U.S., it left behind accumulating snow across parts of New England.

Hurricane Eta
Tropical Depression Twenty-Nine formed at 21:00 UTC on October 31, and then Tropical Storm Eta at 03:00 UTC on November 1. Eta quickly strengthened, reaching hurricane strength by 09:00 UTC on November 2. Eta's rapid intensification continued through that day, and by 21:00 UTC it had grown into a Category 4 hurricane. Eta reached its peak intensity of 150 mph (240 km/h) and a pressure of 923 mbar (27.26 inHg) at 06:00 UTC on November 3. Later that day, at 21:00 UTC, it made landfall south of Puerto Cabezas, Nicaragua, with winds of 140 mph (220 km/h) and a pressure of 940 mbar (27.73 inHg). Eta rapidly weakened over land, moving westward, diminishing to a tropical storm by 09:00 UTC on November 4, and to a tropical depression the following day. By November 7, the depresion had turned northeastward back over the Caribbean, where it regained tropical storm strength. Eta made its next landfall in Cuba's Sancti Spíritus Province at 09:00 UTC on on November 8. Then, after crossing Cuba and the Straits of Florida, Eta made its third landfall, striking Lower Matecumbe Key in the Florida Keys at 04:00 UTC on November 9, with estimated maximum winds of near 65 mph (100 km/h). Next, after moving into the Gulf of Mexico, Eta briefly re-strengthened into a hurricane southwest of Florida on the morning of November 11, before weakening once more to tropical storm strength later in the day due to dry air entrainment. It then turned northeastward and made its final landfall near Cedar Key, Florida at 09:00 UTC on November 12, with winds of 50 mph (85 km/h). The storm weakened over land as it accelerated north-northeastward, emerging over the Atlantic Ocean near the Florida–Georgia state line later that day. Eta transitioned into an extratropical cyclone on November 13 while moving northeastward off the coast of the Carolinas.

Hurricane and tropical storm watches and warnings were issued along the Caribbean coast of Honduras and of Northeastern Nicaragua as Eta approached. Eta knocked down power lines and trees while damaging roofs and causing flooding in and around Puerto Cabezas. Overall, more than 210 fatalities across Central America were attributed to the storm, including 74 in Honduras, 53 in Guatemala, 27 in Mexico, 19 in Panama, two each in Nicaragua and Costa Rica, and one in El Salvador. Relief efforts were severely hampered when, just two weeks later, Hurricane Iota made landfall approximately 15 miles (25 km) south of where Eta moved ashore. Once the system began to reorganize in the Caribbean, tropical storm watches were issued on November 5, in the Cayman Islands. More watches were issued in parts of Cuba, the northwestern Bahamas, and South Florida. Eta bought heavy rainfall and gusty winds to the Cayman Islands and Cuba, the latter of which was already dealing overflowing rivers that prompted evacuations. Heavy rainfall and tropical-storm force winds were recorded across much of Florida as a result of Eta's two landfalls there, causing widespread flooding; there was one fatality in Florida during the storm.

Tropical Storm Theta
On November 6, the NHC began monitoring an non-tropical area of disturbed weather in the central Atlantic for possible gradual subtropical development. A non-tropical low subsequently formed several hundred miles southwest of the Azores on November 8, and was designated 97L. The system became better organized as it began to detach from a frontal boundary during the following day. At 03:00 UTC on November 10, it developed into Subtropical Storm Theta Satellite images received shortly before 14:00 UTC that afternoon revealed that the storm had sustained winds of 70 mph (110 km/h) and a central pressure of 989 mb (29.21 inHg); this would be its peak intensity. Seven hours later, Theta completed a transition to a tropical storm. By the following morning, the effects of strong southwesterly shear had weakened Theta somewhat, though it soon began to regain some strength, and by 03:00 UTC on November 12, attained maximum sustained winds of 65 mph (100 km/h). Though sea surface temperatures were relatively cold and there was moderate wind shear, the air mass was unstable enough to let Theta maintain its strength. Convection continued to wax and wane around the storm's center as it fluctuated in intensity into the next day before it weakened again on November 14, when most of the deep convection associated with It dissipated. By 09:00 UTC the next day, Theta had weakened to a tropical depression, and it degenerated to a remnant low six hours later.

Hurricane Iota
Tropical Depression Thirty-One developed in the central Caribbean around midday on November 13. Six hours later, the system strengthened into Tropical Storm Iota. Iota began to rapidly intensify on November 14, as convection started to wrap around its center, and by 06:00 UTC the next day, it reached hurricane strength. At 06:00 UTC on November 16, hurricane hunters aircraft reported that Iota had become a Category 3 hurricane. Later that day, at 15:00 UTC, Iota reached Category 5 intensity, and also attained its peak intensity with winds of 160 mph (260 km/h) and a minimum central pressure of 917 mb (27.08 inHg). As Iota was nearing its peak intensity, it passed very close to the Archipelago of San Andrés, Providencia and Santa Catalina, with its eye missing Providencia by only 11 miles (18 km). Iota weakened to a high-end Category 4 hurricane at 03:00 UTC on November 17 as it approached the coast of Nicaragua. At 03:40 UTC, the hurricane made landfall near the town of Haulover, Nicaragua (in Pearl Lagoon municipality), with sustained winds of 155 mph (250 km/h) and a pressure of 920 mb (27.17 inHg); it’s landfall location was approximately 15 miles (25 km) south of where Hurricane Eta made landfall 13 days earlier. Iota then steadily weakened as it pushed westward over Central America, falling below hurricane status at 18:00 UTC. By 09:00 UTC on November 18, Iota weakened to a tropical depression over El Salvador, before dissipating later on that day.

The government of Colombia issued a hurricane warning for Providencia and a hurricane watch for the island of San Andrés on November 14; and a few hours later, hurricane warnings were issued for portions of the Caribbean coast of Nicaragua and of Honduras. Iota damaged much of the infrastructure of Providencia, and caused widespread damaging flooding in Nicaragua, Honduras and Guatemala. There were least 61 storm-related fatalities in the region, which was still recovering from the impacts of Hurricane Eta.

Tropical Depression One-E
A disturbance developed within the Intertropical Convergence Zone (ITCZ) on April 17. The disturbance moved westward within the ITCZ over the next several days,  and after developing a well-defined  center and organized convection, it was designated as Tropical Depression One-E at 06:00 UTC on April 25, about 700 nautical miles southwest of the southern tip of the Baja California Peninsula. Moving northwestward, the depression retained organized deep convection until shortly after 00:00 UTC the next day. Dry air and westerly wind shear caused the depression to weaken and degenerate to a remnant low by 12:00 UTC. The remnant low turned west and opened up into a trough at 18:00 UTC on April 27.

One-E was the earliest forming tropical cyclone in the northeastern Pacific proper (east of 140°W) since the dawn of the satellite era in 1966, surpassing Tropical Storm Adrian of 2017 by two weeks. However, Adrian retains the record for the earliest named storm in the basin.

Tropical Storm Amanda
A broad area of low pressure developed near an area of convection over the far eastern portion of the basin on May 27. Meanwhile, a tropical wave that had left the coast of Africa around May 18 crossed Panama into the Eastern Pacific on May 29. The wave caused the low-pressure area to become more organized and develop a well-defined circulation, and it became Tropical Depression Two-E at 18:00 UTC on May 30. Moving northeastward around the periphery of a large cyclonic gyre over northern Central America, the depression continued to organize and compact in size, strengthening into Tropical Storm Amanda at 06:00 UTC the next day. About four hours later, Amanda made landfall at peak intensity near Las Lisas, Guatemala. Amanda rapidly degenerated as it moved inland, with its center dissipating around 18:00 UTC. The remnants of the system moved northward into the Bay of Campeche and re-developed into the Atlantic Tropical Depression Three at 21:00 UTC on June 1, which would later become Tropical Storm Cristobal.

In El Salvador, torrential rainfall caused significant damage along coastal cities in the country as rivers overflowed and swept away buildings. Amanda killed 14 people in El Salvador, of which at least six died due to flash flooding, and one died from a collapsed home. More than 900 homes were damaged across the country and 1,200 families were evacuated to 51 shelters across La Libertad, San Salvador, Sonsonate, and San Vicente. In the capital, San Salvador, 50 houses were destroyed and 23 vehicles fell into a sinkhole. El Salvador President Nayib Bukele declared a 15-day national state of emergency due to the storm. Movement restrictions in place for the ongoing COVID-19 pandemic were temporarily lifted to allow people to purchase medicines, while hardware stores were allowed to open with limited capacity so people could purchase equipment for repairs.

Tropical Storm Boris
On June 20, the NHC began monitoring a small area of thunderstorms associated with a small low pressure area within the Intertropical Convergence Zone. The system gradually organized and intensified over the next few days and a tight circulation began to emerge from the disorganized thunderstorms surrounding the area on June 23. On the next day, the tight circulation became more well-defined and a circular region of thunderstorms began to develop south of the exposed center. Thus, the NHC initiated advisories on the system, designating it Tropical Depression Three-E. The depression gradually tracked west-northwestward for the rest of the day with little change in strength due to an onset of dry air being drawn into the circulation. By the next day, despite hostile conditions, deep convection began to sporadically appear near the center. Although being poorly organized, a pass from ASCAT indicated the storm was producing 35 kt (40 mph) winds, and as a result the depression was upgraded to tropical storm intensity and provided the name Boris at around 21:00 UTC on June 25. Persistent unfavorable conditions continued to slowly degrade the storm's new central convection over time, and Boris weakened back down to a tropical depression at 09:00 UTC on June 26, just 12 hours after becoming a tropical storm.

By 21:00 UTC June 26, a degenerating Boris crossed 140°W and entered the Central Pacific basin as a tropical depression. Boris continued to crawl west through an increasingly hostile environment into June 27, and the system was downgraded to a remnant low by early on June 28 and thus the last advisory was issued by the Central Pacific Hurricane Center. The remnants of Boris slowly drifted southwest for several days afterwards with occasional bursts of convection occurring near the circulation.

Boris was the first June tropical cyclone in the Central Pacific basin since Tropical Storm Barbara in 2001 and only the second ever recorded, dating back to 1966.

Tropical Depression Four-E
On June 20, the NHC began watching an area of disturbed weather that was expected to form near the coast of Mexico in the next 5 days. By June 22, the disturbance formed coactively with a tropical wave and was expected to consolidate into a tropical depression by the weekend. However, conditions fell short and the system's thunderstorm activity remained disorganized. The disturbance became more broad and conditions only became marginally conducive for any further development, and it eventually was absorbed by another large area of disturbed weather on June 27. This new tropical disturbance quickly consolidated into a more compact and well defined center of thunderstorms by June 29. As convection persisted, the system met sufficient criteria to be declared Tropical Depression Four-E later on June 30 at 03:00 UTC. Nevertheless, the storm's organization was short-lived as it drifted on top of colder waters and as a result convection began to wane. The depression struggled to re-develop any more central convection and became a remnant low later that same day.

Tropical Storm Cristina
A tropical wave emerged off the west coast of Africa on June 20 and progressed west across the Atlantic and Caribbean. Oppressive dry air from the Saharan Air Layer prevented any development during this period. Crossing Central America on July 3, the wave interacted with a monsoon trough and deep convection blossomed and gradually organized. This system developed a defined surface low on July 6 and was classified as a tropical depression about 435 mi (705 km) south of Acapulco, Mexico. Steered along a northwest trajectory by a mid-level ridge, the depression traversed a region of warm water, moist mid-level air, and moderate wind shear; these factors enabled slow intensification. After becoming Tropical Storm Cristina on July 7, the NHC anticipated significant intensification as wind shear was forecast to decrease. However, the shear remained in place and Cristina did not organize as fast as expected. Accordingly, the agency saw higher-than-average intensity forecast errors.

Cristina reached its peak intensity late on July 10 with winds of 70 mph (110 km/h) and a pressure of 993 mbar (hPa; 29.33 inHg) as it passed west of Socorro Island. Uncertainty exists in the storm's peak as subjective Dvorak assessments yielded a peak of 89 mph while scatterometer data and objective Dvorak assessments yielded a peak of 54 mph. Thereafter, the cyclone turned west along the south side of the subtropical ridge. Cristina gradually spun down as sea surface temperatures decreased and the surrounding environment became more stable. The storm degraded into a remnant low on July 12 and degenerated into a trough on July 15 about halfway between Hawaii and the Baja California Peninsula.

Tropical Depression Six-E
At 00:00 UTC on July 9, the NHC began monitoring a tropical wave over Central America for potential development into a tropical cyclone. After emerging off the Pacific coast of Honduras, the wave tracked quickly west-northwestward south of Mexico, where upper-level winds were not very conducive for formation. Nevertheless, the wave grew more well-defined and thunderstorms became more concentrated near the closed surface circulation and low-pressure center, leading to its designation as Tropical Depression Six-E at 21:00 UTC on July 13. Initially expected to strengthen to a tropical storm, the convection associated with the system rapidly waned in the following hours, and the system remained weak and fragile as it moved westward. At 21:00 UTC the next day, just 24 hours after formation, the depression degenerated to a remnant low as its surface circulation opened up into a surface trough. The remnants dissipated shortly afterward.

Unnamed Tropical Storm
At 12:00 UTC on July 15, the NHC began to track a tropical wave moving across the southern portion of the basin. The wave spawned an area of low pressure further west at 12:00 UTC on July 19 and gradually organized, forming into Tropical Depression Seven-E at 00:00 UTC on July 20. Forming over a rather hostile environment, a dry environment, and cool sea surface temperatures (SSTs) operationally appeared to prevent the depression from strengthening. However, post-storm analysis revealed that an improvement in central convection had occurred and a relatively strong band had formed on the northeast side of the system. That coupled with an ASCAT pass which revealed sustained winds of 39 mph (62 km/h) on the south side indicated the depression had intensified to tropical storm strength at 12:00 UTC on July 20. However, the system became devoid of all deep convection due to cold sea surface temperatures despite maintaining its strength and by 06:00 UTC on July 21, Seven-E was downgraded to a post-tropical cyclone without being named due to continued unfavorable conditions. The low then spun down and dissipated by 00:00 UTC on July 22.

Hurricane Douglas
A tropical wave emerged off the west coast of Africa over the Atlantic Ocean on July 8 and traveled west. Crossing South and Central America from July 12–15, the system later entered the Eastern Pacific basin. Over the next five days, convection gradually organized around a consolidating surface low and a tropical depression developed on July 20 about 805 mi (1,295 km) southwest of the southern tip of Baja California Sur. Traveling along the south side of a mid-level ridge, the system steadily organized within a favorable environment and became a tropical storm later that day. Intensification was briefly halted by intrusions of dry air, but once this abated Douglas underwent rapid intensification. The system became a hurricane late on July 22 and reached its peak strength as a Category 4 hurricane early on July 24; maximum sustained winds were estimated at 130 mph (215 km/h) and its central pressure fell to 954 mbar (hPa; 28.17 inHg). Shortly thereafter, the hurricane crossed into the Central Pacific basin on a course toward Hawaii. Lower sea surface temperatures led to gradual decay of the hurricane as it approached the state. On July 27, the center of Douglas passed just 60 mi (95 km) north of the main Hawaiian Islands; despite its proximity, effects were negligible. Increasing wind shear caused Douglas to rapidly unfold on July 28, resulting in its degradation to a tropical storm and ultimately its dissipation later that day well to the southeast of Midway Atoll.

Hurricane Elida
On August 4, the NHC highlighted the potential for a tropical wave to coalesce into an area of low pressure southwest of Mexico within the next five days. Two days later, the wave moved across Central America into the Pacific basin, and the disturbance gradually became more organized over the next few days. At 03:00 UTC on August 9, the NHC declared that the system had become Tropical Depression Nine-E, as the system had developed persistent convection and a closed circulation. At 09:00 UTC, the depression was upgraded to Tropical Storm Elida. Thereafter, Elida began rapid intensification, though the presence of a slight amount of dry air prevented the storm from continuing to intensify for a short time. At 21:00 UTC on August 10, Elida was upgraded into a hurricane a few miles north of Socorro Island. The next day, Elida continued to gain strength and ultimately peaked at Category 2 intensity on the Saffir-Simpson Scale. Shortly afterwards, Elida started rapidly weakening due to dry air, wind shear, and cold waters, and was downgraded to a tropical storm at 15:00 UTC on August 12. At 03:00 UTC on August 13, Elida was downgraded to a post-tropical cyclone by the NHC.

Tropical Depression Ten-E
On August 10, an area of disturbed tropical weather formed about 1,500 miles west-southwest of Baja California, slowly moving westward, and forming a low pressure area the next day. This system gradually organized in favorable conditions, and at 09:00 UTC on August 13, the system developed into a tropical depression, being designated Ten-E. The system remained relatively unchanged for the next three days as it was affected by moderately strong shear that inhibited intensification but allowed the system to remain tropical. The depression finally became post-tropical at 21:00 UTC on August 16. On August 21, Ten-E again entered a favorable environment for development as its remnants continued southwest, and was briefly monitored by the Central Pacific Hurricane Center for possible redevelopment. Despite this, the storm failed to regenerate and it was last mentioned on August 23.

Tropical Storm Fausto
An elongated region of low pressure over the central portion of the basin spawned 2 areas of disturbed weather between the Revillagigedo Islands on August 14. The southwestern portion of this trough slowly moved northwards and became more organized while the northeastern section struggled to become more defined over the day. Despite remaining in favorable conditions, the northeastern disturbance failed to develop and was subsequently absorbed into the southwestern disturbance. This system quickly became sufficiently organized enough to be declared a tropical depression by 03:00 UTC on August 16. Initially not forecast to become a tropical storm, the depression quickly developed a central region of thunderstorms and satellite estimates further indicated the storm had become Tropical Storm Fausto just 12 hours later. However, Fausto quickly succumbed to cooling sea surface temperatures and thunderstorm activity near the center began to decrease. Fausto then weakened to a tropical depression at 03:00 UTC August 17 as it continued northwest into the cool isotherm. Fausto degenerated into a remnant low later that day.

A large plume of moisture brought northwards by Fausto generated massive thunderstorms across a large portion of Northern California, beginning on August 16. These storms produced mostly dry lightning with little to no rain, with almost 11,000 lightning strikes occurring in the state between August 16 and 17. The lightning from these storms sparked 367 fires across the state, several of which became very large in a short period of time, threatening thousands of structures and forcing thousands of people to evacuate. The massive SCU Lightning Complex, August Complex, CZU Lightning Complex, and North Complex fires were connected to the thunderstorms associated with Fausto.

Hurricane Genevieve
On August 10, a disturbance formed west of Central America and began to be monitored by the NHC. On August 13, this disturbance developed into a trough of low pressure southwest of Mexico. The disturbance gradually organized, and on August 16, the system became a tropical depression, receiving the designation Twelve-E at 15:00 UTC. The depression rapidly strengthened and became a tropical storm 6 hours later at 21:00 UTC, receiving the name Genevieve. Genevieve continued to strengthen rapidly overnight and became a hurricane on August 17, reaching 1-minute winds of 75 mph (120 km/h). Genevieve continued to intensify quickly, and on the next day, at 09:00 UTC, Genevieve explosively intensified into a Category 3 major hurricane. Three hours later, Genevieve intensified further into a Category 4 hurricane, and formed a very well-defined and clear eye. Afterward, Genevieve gradually began to weaken, dropping to Category 3 status by 03:00 UTC on August 19, possibly due to encountering colder water from the cold wake left behind by Hurricane Elida. Genevieve continued a gradual weakening trend for the next several hours, but later that day, data from an NHC Reconnaissance Flight indicated that Genevieve was rapidly weakening, with the storm dropping to Category 1 status by 21:00 UTC that day. On August 20, Genevieve turned northwestward and passed very close to Cabo San Lucas, at the southern tip of the Baja California Peninsula, and the system weakened further into a tropical storm at 18:00 UTC. By 21:00 UTC on August 21, Genevieve had degenerated into a post-tropical cyclone, after having no deep convection for 12 hours.

Numerous tropical cyclone watches and warnings were issued for parts of Baja California beginning on August 17. A total of 6 people died in storm-related incidents across Mexico.

Tropical Storm Hernan
On August 17, the National Hurricane Center began tracking a disturbance off the west coast of Mexico. Late on August 20, this disturbance formed a broad area of low pressure just southwest of extreme southwestern Mexico. Over the course of the next five days, the system slowly organized, and at 09:00 UTC on August 26, it developed into Tropical Depression Thirteen-E. 12 hours later at 21:00 UTC, the system strengthened into a tropical storm, receiving the name Hernan. A poorly organized storm, the system struggled to intensify in the high-shear environment within a larger scale region of monsoonal rotation. Despite unfavorable conditions, scatterometer data found Hernan had slightly intensified to 45 mph (75 km/h) by 03:00 UTC on August 27. Hernan's peak intensity proved to be short lived as it turned west and moved into the Gulf of California, degenerating into a remnant low over Baja California Sur at 15:00 UTC, August 28. In Mexico, 97,000 customers lost electricity. Hernan dropped precipitation amounts of 5-9 inches (127-228 mm) of rainfall from Michoacan to Nayarit, causing flash flooding and mudslides in the Mexican states of Jalisco and Colima. It prompted many families to flee their homes. At least 400 people were evacuated in Jalisco, and 18 people stuck on their roof in the state had to be rescued. In Cihuatlán, roughly 365 residents evacuated into shelters. A sinkhole shut down a portion of Mexican Federal Highway 80 between Santa Cruz and San Patricio, a mudslide closed down another part of the freeway near Lazaro Cardenas. The Cuixmala River overflowed its banks, causing parts of Mexican Federal Highway 200 to shut down. The town of La Manzanilla was mostly inundated by floodwaters which caused a bridge near the town to collapse. Several schools were damaged by Hernan in the state of Colima. In Tamala, a parota tree fell on a road, blocking traffic. In Manzanillo, some homes and streets were damaged and covered with mud. In Nayarit, a mudslide occurred on a hill behind a populated neighborhood in Xalisco, however no damage has been reported from this incident. Despite Hernan weakening into a tropical depression before landfall in Baja California Sur, local weather services in the area advised residents to take extreme precautions.

Tropical Storm Iselle
Late on August 24, a small low pressure system developed several hundred miles southwest of the southern tip of the Baja California peninsula, near the disturbance that would later become Tropical Storm Hernan. As environmental conditions for development became more favorable, the circulation of the system gradually became better defined, and the system developed into Tropical Depression Fourteen-E at 15:00 UTC on August 26 over the open Pacific Ocean. The cyclone reached tropical storm strength 6 hours later at 21:00 UTC, receiving the name Iselle. Similarly to Tropical Storm Hernan, Iselle was trapped within a larger scale region of rotation and struggled to organize from an offset of wind shear. However, despite the moderate to strong wind shear, Iselle strengthened to 50 mph (85 km/h) over the next 12 hours while moving slowly northeastward. Iselle continued to intensify and at 15:00 UTC on August 28, Iselle attained its peak intensity of maximum sustained winds of 60 mph (95 km/h) and a minimum central pressure of 997 mbar. Iselle then made a very close pass to Clarion Island, where tropical-storm force winds were reported, before weakening thereafter. Iselle became post-tropical later on August 30 as it headed north, near the Baja California Peninsula.

Tropical Storm Julio
On September 4, the remnants of Hurricane Nana from the North Atlantic emerged over the Gulf of Tehuantepec and subsequently began to organize. By September 5, a well defined and compact surface circulation developed with the remnant low, and eventually the system's thunderstorm activity became organized enough for the system to be dubbed Tropical Storm Julio later that day, as the storm was already producing gale-force winds. A very small cyclone with tropical-storm force winds only extending 35 miles from the center, Julio slowly intensified given its favorable environment. Switching to a quick pace west-northwestward, the storm quickly weakened on September 6 despite forecasts of strengthening. Julio later opened up into a trough of low pressure and became a post-tropical low on 09:00 UTC, September 7.

Julio produced heavy rainfall over portions of southwestern Mexico and large surf of 1–3 meters affected some beaches in the area.

Tropical Storm Karina
On September 9, the NHC began monitoring an area of disturbed weather to the south of Mexico. Early the next day, a broad area of low pressure formed within the system as it continued to produce disturbed weather. By 03:00 UTC on September 13, the disturbance became organized enough to be designated as a tropical depression. Just six hours later, the depression strengthened into Tropical Storm Karina while located 455 miles southwest of Baja California. Karina slowly strengthened over the next couple of days, reaching its peak intensity around 09:00 UTC on September 15. Karina then weakened below tropical storm status late on September 16, before degenerating into a post-tropical cyclone by 09:00 UTC the next day.

Tropical Storm Lowell
On September 19, the NHC began monitoring an area of disturbed weather south of Mexico for potential tropical development. At 18:00 UTC on September 20, the disturbance gained sufficient organization to be designated a tropical depression. 24 hours later, the depression strengthened into Tropical Storm Lowell. Slowly strengthening for 36 hours onward, Lowell reached its peak intensity at 06:00 UTC on September 23 with maximum sustained winds of 50 mph (85 km/h) and a barometric pressure of 1001 millibars. Lowell remained poorly organized as it passed close to Clarion Island later that day. Lowell gradually weakened once turning westward on September 24 as it moved into cooler waters and as vertical wind shear increased. At 18:00 UTC on September 25, Lowell degenerated into a post-tropical cyclone after lacking deep convection for several hours.

Hurricane Marie
On September 24, the NHC first noted the possibity of tropical cyclogenesis offshore Mexico. Three days later, an area of low pressure formed. Over the next two days, the disturbance rapidly organized as it moved west-northwestward, and at 09:00 UTC on September 29, the system became sufficiently organized to be classified as Tropical Depression Eighteen-E. Just 12 hours later, the depression became Tropical Storm Marie. On September 30, Marie underwent rapid intensification and became a hurricane by 21:00 UTC. Further intensification occurred and 12 hours later, Marie became a Category 2 hurricane. Continuing to intensify, Marie intensified to a Category 3 major hurricane at 03:00 UTC on October 2 before it reached its peak strength as a Category 4 hurricane six hours later with winds of 130 mph (215 km/h) and a pressure of 947 mb (hPa; 27.97 inHg) Marie maintained its strength for a day or so before it began to rapidly weaken due to cooler waters and dry air infusion. It dropped below major hurricane status at 09:00 UTC on October 4 and below hurricane status at 03:00 UTC on October 5. It center became exposed, although the weakening trend slowed as convection continued to fire on its northeast side. After a brief resurgence late on October 5, Marie convection's became too weak and too far from its center for it to remain a tropical cyclone and it was downgraded to a remnant low at 03:00 UTC on October 7.

Tropical Storm Norbert
Early on September 30, the NHC began noting the possibility of an area of low pressure forming southwest of Mexico. The area of low pressure finally formed early on October 4 and quickly organized into a tropical depression by 21:00 UTC the next day. At 09:00 UTC on October 6, the depression strengthened into Tropical Storm Norbert. After spending 36 hours at tropical storm strength, Nobert weakened back into a tropical depression at 21:00 UTC on October 7. Norbert maintained its status as a tropical depression until it degenerated into a remnant low early on October 10. After Norbert degenerated into a remnant low, the NHC began tracking the low for possible redevelopment, as upper level winds were expected to become more favorable. The remnants began showing signs of organization over the next two days. On October 13, the low began to quickly organize, and at 21:00 UTC that day, the NHC declared that Norbert had regenerated into a tropical depression several hundred miles southwest of the Baja California peninsula. Soon afterwards, it unexpectedly strengthened into a tropical storm again at 03:00 UTC on October 14. However, this restrengthening was short-lived, as Norbert began weakening again and became a tropical depression 18 hours later. It eventually became post-tropical yet again at 09:00 UTC on October 15 due to unfavorable conditions.

Tropical Storm Odalys
On October 27, the National Hurricane Center (NHC) began noting the possibility of a trough of low pressure to form south of the Gulf of Tehuantepec. On November 1, that trough of low pressure formed several hundred miles to the southwest of Mexico. At 21:00 UTC on November 3, the trough of low pressure organized into Tropical Storm Odalys. Odalys slowly strengthened reaching sustained winds of 45 mph (70 km/h) just 24 hours later. However, the storm maintained a disorganized appearance, with most of Odalys' convection displaced north of the center. At 09:00 UTC on November 5, Odalys reached its peak intensity with winds of around 50 mph (80 km/h) and a pressure of 1000 mbar. Odalys maintained this intensity for 12 hours before weakening. Odalys degenerated into a post-tropical cyclone at 03:00 UTC on November 6.

Tropical Storm Polo
On November 10, the NHC first noted the possibility of a tropical cyclone to form off the coast of Mexico. Two days later, a low pressure area formed. The system soon began to rapidly organize, with the NHC stating that it had a high chance of formation in the next five days on November 14. However, on the next day, the convection deteriorated and the system became increasingly ill-defined, and thus the NHC lowered the chances of formation to 30% on November 16. On the next day, the disturbance rapidly reorganized due to locally favorable conditions in the region and at 21:00 UTC, it was declared a tropical depression. The depression strengthened overnight into a tropical storm and was named Polo as it began its curve westwards. Polo strengthened slightly over November 18, but weakened after another 24 hours to a tropical depression yet again. Due to failing to re-produce central convection, Polo became a remnant low and the last advisory on the storm was issued on November 19.

Typhoon Vongfong (Ambo)
After 4 consecutive months of inactivity in the Western Pacific basin, a low-pressure area was first noted on May 9 by the JTWC near Micronesia and was given a medium chance of developing into a tropical cyclone. The following day, the JMA declared that it had developed into a tropical depression to the east of Mindanao, Philippines and was expected to slowly move west. The JTWC then issued a Tropical Cyclone Formation Alert (TCFA) for the embryonic system just hours later while convection began to gradually obscure the center. Later that day, the PAGASA followed suit and upgraded the system to a tropical depression, assigning it the name Ambo, as it became the first tropical cyclone to enter their area of responsibility for 2020.

The system began to slowly drift westwards throughout the following days, gradually intensifying with occasional convective bursts occurring near the slightly elongated circulation. On the next day, the JTWC upgraded Ambo into a tropical depression, designating it as 01W. The storm gradually intensified throughout the day, as signified by a well-defined rain band developing on the northwestern side, and began to turn north. At this time, the JMA upgraded 01W to a tropical storm and assigned it the first name of the year, Vongfong. Shortly after, the JTWC followed and upgraded the system to tropical storm intensity. Utilizing favorable conditions with low wind shear, 29–30 °C waters, and excellent outflow, Vongfong began to rapidly intensify by early May 13. Shortly after, the JMA upgraded the system to a severe tropical storm. Soon after, the JTWC upgraded the storm to a Category 1 typhoon with 1-minute sustained winds of 130 km/h (80 mph) as the structure quickly improved. The PAGASA and JMA would then upgrade the system to a typhoon later in the day, with the JTWC quickly upgrading the system to a Category 2 typhoon as the eye became clearer. A few hours later, Vongfong intensified to a Category 3-equivalent typhoon. Then, the storm later went an eyewall replacement cycle, quickly finishing the cycle while fluctuating in intensity. At 12:15 pm PST on May 14, Vongfong made its first landfall in San Policarpo, Eastern Samar. Vongfong gradually weakened shortly after, crossing over the Ticao Pass as it moved further inland. By the succeeding day, PAGASA recorded five more landfalls: hitting the islands of Dalupiri Island, Capul Island, Ticao Island, Burias Island, and San Andres, Quezon in Luzon Island's Bondoc Peninsula. Ambo weakened into a Category 1 storm due to these multiple landfalls, although the storm was situated in favorable atmospheric conditions. The system further weakened on May 15, and was downgraded by both the JMA and PAGASA to a severe tropical storm, with the JTWC downgrading it to a tropical storm as well. Then, Vongfong made its 7th landfall in Real, Quezon, and began to head further inland into Luzon. Vongfong then further weakened and was downgraded by the JMA and the PAGASA into a tropical storm. The weakening trend continued, and by May 16, Vongfong emerged into the Luzon Strait as a low-end tropical storm, with the storm's center exposed as the result of the mountainous terrains of the Luzon landmass. After emerging, 6 hours later, the JTWC downgraded Vongfong into a tropical depression, and issued their final warning. Soon after, PAGASA followed suit, and the JMA as well. The remnants of the storm fully dissipated by May 17, with PAGASA downgrading the storm's remains into an low-pressure area.

In preparation for the incoming typhoon, Tropical Cyclone Wind Signal (TCWS) #3 warnings were issued for Northern Samar and the northern portion of Eastern Samar. According to the NDRRMC, Typhoon Vongfong (Ambo) left ₱1.57 billion (US$31.1 million) worth of damages in agriculture, and left 5 dead, as of May 27. With the multi-billion peso damages in the Philippines, the name Ambo was retired by the PAGASA and will be replaced with a new name for the 2024 Pacific typhoon season.

Tropical Storm Nuri (Butchoy)
On June 10, the JMA began monitoring on a weak tropical depression that had developed to the east of the Philippine island of Samar in Visayas. During the next day, the PAGASA began tracking the system, giving the local name Butchoy. The storm then made its first landfall in Polillo Island in Quezon at 5:30 pm PHT, and making its second landfall in Infanta, Quezon shortly thereafter. Soon after, the JTWC issued a Tropical Cyclone Formation Alert for the storm. Afterwards, the JTWC officially upgraded Butchoy to a tropical depression, and designated it as 02W. With a favorable environment with low vertical wind shear, moderate equatorial outflow and 30–31 °C sea surface temperatures, Butchoy started to intensify in the West Philippine Sea, becoming a tropical storm and receiving the name Nuri from the JMA later on the same day. Then, PAGASA issued their final warning on Nuri as it exited the Philippine Area of Responsibility. By the next day, Nuri intensified further and subsequently peaked in intensity, with the JMA analyzing the storm's peak winds of 75 km/h (45 mph). Six hours later, the JTWC upgraded Nuri to a tropical storm. However, later in the same day, the JTWC downgraded Nuri into a tropical depression, citing that the storm has drifted into high vertical wind shear. The JMA followed suit, downgrading Nuri into a depression. The JTWC issued their final warning on Nuri as the storm subsequently made landfall in Yanjiang, China. The JMA followed suit six hours later, issuing their final warning on the system.

The PAGASA issued Tropical Cyclone Signal No. 1 for western Mindanao, southern Luzon, and Visayas on June 11 as Butchoy neared the Philippines. The combination of the system and prevailing southwesterly winds brought showers and thunderstorms across the Philippines. Heavy rainfall in Albay led to the activation of disaster risk management officials and other emergency assets. The rains from the tropical depression prompted PAGASA to declare the start of the rainy season in the Philippines on June 12, 2020, which was also during the country's Independence Day. In Hong Kong, Nuri brought heavy rain. One person also drowned due to rough waters.

Tropical Depression Carina
After about one month of inactivity, on July 11, the JMA designated an low-pressure area near Luzon as a tropical depression. The next day, the JTWC designated the depression as an invest and was given a low chance of developing, and later upgraded to a medium chance. On the following day, the PAGASA upgraded the low-pressure system to a tropical depression and named it Carina.

Over an environment favorable for further development, with low vertical wind shear, established equatorial outflow and 28–29 °C sea surface temperatures, Carina generally moved north-northwest until midday (12:00 UTC) on July 14, when Carina rapidly weakened into a low-pressure area, due to unfavorable environment of strong wind shear and diffluent easterly flow. PAGASA then issued their final advisory to Carina, and the remnants dissipated on July 15.

As the low-pressure system was named Carina, PAGASA immediately hoisted Signal #1, the lowest of their storm warning signals, to Batanes, Babuyan Islands and the northeastern portion of Cagayan. Due to heavy rainfall caused by Carina, the storm caused some minimal damage on Ilocos Norte, Abra and Isabela.

Typhoon Hagupit (Dindo)
On July 31, JMA began monitoring a weak tropical depression that developed in the Philippine Sea. Later, PAGASA later named the depression Dindo. By the next day, the Joint Typhoon Warning Center designated Dindo as 03W. With favorable conditions of low vertical wind shear, strong equatorial outflow and 31 °C sea surface temperatures, Dindo intensified into a tropical storm on midday of the same time, and the Japan Meteorological Agency named it as Hagupit. Hagupit then began intensifying in the Philippine Sea, and by August 2, Hagupit was upgraded into a typhoon by the JTWC. The JMA later upgraded Hagupit to a severe tropical storm late on August 2. As Hagupit exited the Philippine Area of Responsibility (PAR), the PAGASA issued its final bulletin on the system. Hagupit was then upgraded into typhoon status by the JMA on August 3, and will later peak in intensity with a pressure of 975 hPa. At around 19:30 UTC, Hagupit made landfall in Wenzhou, China, with winds of 85 mph and pressure of 975 mbar (hPa). After its landfall, Hagupit gradually weakened over China, and by early August 4, the JTWC downgraded the typhoon into a tropical storm. Around midday of the same day, JTWC downgraded Hagupit into a tropical depression and later issued their final advisories on the storm, but the JMA still monitored Hagupit as a tropical storm. The system later would undergo an extratropical transition, a process which got completed on August 6, and the JMA issued their final advisory on the extratropical Hagupit.

In advance of Hagupit, Chinese officials ordered the evacuation of areas vulnerable to flooding. Hagupit caused torrential rainfall over portions of China peaking at 13.11 inches (333 mm) in the Jingshan district of Wenzhou. 15 people were reported dead across South Korea, 6 of them following a landslide in South Chungcheong Province, 11 people were reported missing, and 7 people were injured.

Tropical Storm Sinlaku
On July 29, a tropical disturbance formed and was situated a couple hundred miles east of Manila, Philippines. Struggling to consolidate, the disturbance crossed Luzon with little to no organization and began organizing in the South China Sea. Environmental conditions became conducive for development, and the JMA declared that a tropical depression had formed in the early hours of July 31. Then early on August 1, the depression intensified into Tropical Storm Sinlaku. The storm failed to intensify much afterward, and during the following day, Sinlaku made landfall on northern Vietnam. Shortly thereafter, both agencies issued final advisories on the storm.

Sinlaku produced heavy rain across central and northern Vietnam, resulting in significant flooding. Two people died, one from a collapsed embankment and the other from flash flooding. Thousands of homes were inundated and crops suffered extensive damage. Damage in the nation was about nearly 5.4 billion đồng (US$232,900). Flash floods across Thailand also killed two people.

The remnants of Sinlaku emerged in the Indian Ocean and intensified into a well marked low pressure area between August 5–8, recreating a lot of torrential rain in portions of India.

Tropical Storm Jangmi (Enteng)
On August 6, the Philippine Atmospheric, Geophysical and Astronomical Services Administration started to monitor a low-pressure area that developed well east of Virac, Catanduanes. On the next day, the Japan Meteorological Agency designated the low-pressure area as a weak tropical depression. Despite a broad and elongated low-level circulation center, it gradually organized, prompting the Joint Typhoon Warning Center to issue a Tropical Cyclone Formation Alert on the depression.

Early on next day, the PAGASA upgraded it to a depression, naming it Enteng. Later around the same day, the JTWC designated the depression as 05W. But, near end on the same day, the Japan Meteorological Agency upgraded the depression to a tropical storm, receiving the name Jangmi. As such, Jangmi became the fifth named tropical storm of the 2020 typhoon season. On August 9, Jangmi was upgraded into a tropical storm by the JTWC. Despite being at favorable conditions of low vertical shear and 29–30 °C sea surface temperatures, an upper-level low present to the west of the system prohibited the broad Jangmi to organize further. Around the same time, the PAGASA dropped advisories on Jangmi as it quickly exited the Philippine Area of Responsibility. Moving northward at 23 knots, the JMA reported that Jangmi already peaked at 45 knots (50 mph; 85 km/h). Around 05:50 UTC on August 10, Jangmi made landfall on the southern tip of Geojedo, Gyeongsang Province in South Korea. The JTWC issued their final advisories on Jangmi around 15:00 UTC of the same day, and the JMA issued their final advisory early on the next day, August 11.

Jangmi dropped drenching rainfall through the Ryukyu Islands of Japan, with a peak amount of 2.2 inches (55.8 mm) recorded on the island of Kumejima. In South Korea, Jangmi dropped up to 2.6 inches (66.04 mm) of precipitation, in an area already hard hit by flooding in the months previous to Jangmi.

Tropical Depression 06W (Gener)
Due to the fact that the disturbance already had tropical-storm-force winds, it was immediately declared a tropical storm by the JTWC on August 9. The next day, the tropical depression reached its peak intensity of 35 mph with an unusually high pressure of 1012 mbar. Soon afterwards 06W began to gradually weaken, and at 15:00 UTC on August 10, the JTWC downgraded 06W to a tropical depression.

After moving generally westward, the system began to move to the southwest and, at 20:00 UTC (4:00 am, August 13 PST), it entered the Philippine's area of responsibility and was given the name Gener by PAGASA.

Severe Tropical Storm Mekkhala (Ferdie)
Another area of persistent convection formed within the proximity of the trough that would also spawn Tropical Storm Jangmi On August 7, west of Luzon. As Jangmi became the dominant system in the area, this low-pressure area remained disorganized. However, on the next day, as Jangmi moved away from the area, the system began to organize, and on August 9, the JTWC upgraded the storm to a Tropical Depression. Soon after, at 8:00 pm. PST, the PAGASA followed and upgraded the storm and gave it the name Ferdie. At 07:30 CST on August 11 (23:30 UTC on August 10), Mekkhala made landfall at Zhangpu County in Fujian, China shortly after peak intensity.

Mekkhala forced a Signal No. 1 warning to be placed for the Ilocos region in the Philippines. Mekkhala brought monsoonal conditions to portions of Luzon, shortly after its formation. Although remain well offshore Taiwan, the storm still brought heavy rainfall to the island.

In China, local officials suspended ferry services and told ships to return to port, in preparation for Mekkhala. The China Meteorological Administration issued a Level III emergency response, while flood control workers were sent to areas which were hit by Mekkhala. Mekkhala dropped torrential rainfall over China with amounts of up to 7.874 inches (200 mm) reported in some areas. Train services were halted and flights were canceled at local airports as Mekkhala moved onshore. In Zhangzhou, Fujian, damage from the storm reached 1.1 billion yuan (US$159 million).

Severe Tropical Storm Higos (Helen)
A new tropical depression formed from the Intertropical Convergence Zone east of Luzon on August 16. At 15:00 UTC, the PAGASA named the system Helen and began issuing severe weather bulletins for the tropical depression, but dropped the alerts as Helen left the Philippine area of responsibility after 4 hours. The Hong Kong Observatory and Macau Meteorological and Geophysical Bureau upgraded Higos into a marginal typhoon prior to landfall, with sustained hurricane-force winds in Macau indicating such an intensity. Higos made landfall over Zhuhai, Guangdong at peak intensity at around 06:00 CST on August 19 (22:00 UTC on August 18).

In preparation for Higos, the Hong Kong Observatory raised the number 9 tropical cyclone warning signal in Hong Kong to warn of the possibility of hurricane-force winds. Winds generally reached gale to storm force over the southern part of Hong Kong under the influence of Higos' small circulation. The Macao Meteorological and Geophysical Bureau issued the number 10 signal, the highest signal, at 05:00 am local time. Over 65,000 people evacuated and schools were closed across these areas. Although heavily populated areas of China were directly hit by Higos, damage was mostly limited to downed trees and power outages. Two campers who were unaware of the approaching storm had to be rescued from Tap Mun Island after arriving on August 14. The storm also left 7 deaths and 45 billion đồng (US$2 million) in damages in Vietnam.

Typhoon Bavi (Igme)
On August 19, the JTWC began monitoring a broad area of low pressure situated a couple hundred miles northeast of the Philippine archipelago. By the next day, the system rapidly organized, and the JTWC subsequently issued a Tropical Cyclone Formation Alert (TCFA). On August 21, the area of low pressure became Tropical Depression 09W. At 15:00 UTC, the PAGASA named the system Igme and issued a severe weather bulletin for it. By the next day, Igme intensified into a tropical storm, according to the JMA and was given the name Bavi, subsequently prompting the JTWC to follow suit and upgrade 09W from a tropical depression to a tropical storm. Favorable conditions allowed Bavi to rapidly intensify, and by 12:00 UTC on August 22, the system became a severe tropical storm. As the system left the Philippine Area of Responsibility, the PAGASA stopped issuing weather bulletins for the severe tropical storm. Bavi's period of rapid intensification was brief, and it began a slow intensification phase on August 23.

On August 24, Bavi slowly intensified, and it was later upgraded by the JMA into a typhoon. Later on that day, it became a Category 2 typhoon. By the next day, Bavi intensified even more to become a major Category 3 typhoon. As Bavi moved closer to the Korean peninsula, one person died in Jeju island on August 25. At around 00:30 UTC on August 27, Bavi made landfall over North Pyongan Province, North Korea. After that, Typhoon Bavi transitioned into an extratropical storm in Manchuria, China.

Typhoon Maysak (Julian)
A low-pressure area east of the Philippines consolidated into a tropical depression on August 27, and simultaneously, a Tropical Cyclone Formation Alert was issued for the system. Early on August 28, PAGASA upgraded it to a tropical depression with the local name Julian, shortly before the JMA upgraded it to a tropical storm and assigned the international name Maysak. Subsequently, the JTWC upgraded Maysak to a tropical storm too, and then the JMA upgraded it to a severe tropical storm despite its elongated low-level circulation center. and two hours later, PAGASA followed and also upgraded the system to typhoon status. Later on that day, it became a Category 2 typhoon. By the next day, Maysak intensified even more to become a major Category 3 typhoon. Then later on afternoon, it was upgraded to a Category 4 typhoon. Soon, Maysak began to weaken bit-by-bit as it passed the East China Sea, slowing back down to a Category 3 storm.

Typhoon Maysak then made landfall near Busan, South Korea at 02:20 KST on September 3 (17:20 UTC on September 2), with 10-minute maximum sustained winds at 155 km/h (100 mph) and the central pressure at 950 hPa. equivalent to a Category 2 typhoon. After that, it crossed the Sea of Japan and hitting North Korea into Jilin, Manchuria in China. Soon after, Typhoon Maysak degenerated into an extratropical low in northeast China.

On September 2, the Panamanian-registered animal transport ship Gulf Livestock 1 transmitted a Mayday and launched lifeboats, at least one of which was found. The ship was west of Japan's Amami Ōshima Island. The Japan Coast Guard has said that the freighter was carrying a crew including 39 Filipinos, 2 Australians, and 2 New Zealanders when it disappeared. The cargo was 5,867 cattle, loaded in Napier, New Zealand, and bound for the port of Jingtang in Tangshan, China. Two fatalities occurred in South Korea where also 120,000 households lost power. In North Korea, Maysak dropped 15.157 inches (385 mm) of precipitation in Wonsan.

Typhoon Haishen (Kristine)
By the next day, the disturbance had quickly organized, and the JTWC issued a Tropical Cyclone Formation Alert (TCFA) for the low-pressure area, and by the next day, it intensified into Tropical Depression 11W. Traversing generally southwestward, the depression quickly intensified into a tropical storm.

Upon entering the Philippine Area of Responsibility (PAR), the Philippine Atmospheric, Geological and Atmospheric Services Administration (PAGASA) named the system Kristine. Early on September 4, the JTWC assessed that Haishen became a Category 4-equivalent super typhoon – with 1-minute sustained wind speeds of 135 kt (155 mph; 250 km/h), with a clear, symmetrical eye visible on satellite imagery. On September 5, as Haishen's latitude increased, the ocean heat content in the area decreased, which disrupted the system's core and caused its eye to appear ragged on satellite imagery, subsequently indicating weakening, and dropping below super typhoon status. Later that day, the system left the PAR and PAGASA issued its last bulletin on the typhoon.

As the system continued its northward track toward the Japanese archipelago, it continued to weaken and became a category 3 typhoon, and not too long after it dropped to a category 2 typhoon as it neared the Southern Ryukyu Islands of Japan. A mandatory evacuation order was issued for western Japan as millions of people evacuated accordingly. Haishen made landfall in Ulsan, South Korea at around 09:00 KST (00:00 UTC) on September 7,

Haishen caused two fatalities in Japan, while four others went missing after a mudslide occurred in Miyazaki Prefecture. Two more fatalities occurred in South Korea and widespread flooding occurred in neighboring North Korea.

Tropical Depression 12W
On September 10, the JMA began tracking a tropical disturbance to the north-northwest of Iwo-To, Japan. At 15:00 UTC that day, the JTWC issued a Tropical Cyclone Formation Alert on the system. By 03:00 UTC on September 12, the JTWC declared the system as a Tropical Depression 12W. However, the JTWC issued its final warning on the system later that day.

Tropical Storm Noul (Leon)
On the morning of September 15, the JTWC issued a tropical cyclone formation alert for a tropical system forming in the Philippine Sea. The JTWC later followed at 15:00 UTC as they issued their first warning on the system as Tropical Depression 13W. Since the depression formed inside of the Philippine Area of Responsibility (PAR), the PAGASA immediately issued a severe weather bulletin on the storm and named the system Leon. At 21:00 on September 16, the storm left the PAR and PAGASA issued its final warning on the system. At 03:00 UTC September 18, Noul made landfall between Quảng Trị and Thừa Thiên-Huế provinces. At 09:00 UTC, the JTWC issued its final warning on the system. After being downgraded to a low pressure area (LPA), Noul followed a westward path and emerged in the Indian Ocean.

A few days before the storm hit Vietnam, the Vietnamese government closed three airports and evacuated more than one million people in the affected areas. Noul damaged homes and knocked down trees and power lines in Hue, Vietnam. Heavy precipitation amounts peaking at 310 mm (12.20 inches) fell in Da Nang. The storm caused 6 deaths and 705 billion đồng (US$30.4 million) in damage.

Severe Tropical Storm Dolphin (Marce)
On September 20 at 06:00 UTC, as the system strengthened in the extreme northeast corner of the Philippine Area of Responsibility, PAGASA upgraded the system to a tropical depression, giving it the local name Marce. At the time, the JTWC only recognized the system as an area of convection and only issued a medium level of warning for the system. The JTWC upgraded the system to a tropical storm at 12:00 UTC. On September 21 at 03:00 UTC, the system left the Philippine Area of Responsibility. The system then intensified into a tropical storm on the southern seas of Japan, earning the international name Dolphin from the JMA. After the storm transitioned into an extratropical cyclone, the JTWC issued its final warning on the system on September 24 at 03:00 UTC.

Severe Tropical Storm Kujira
The storm drifted north-northwestwards before recurring to the northeast while intensifying into a Category 1-equivalent typhoon early on September 29. Kujira weakened to a tropical storm 12 hours after it intensified into a typhoon due to very high wind shear and cool waters. At 21:00 UTC, the JTWC issued the last advisory for the system.

Typhoon Chan-hom
On October 2, the JTWC began to monitor a large area of thunderstorms in the open Pacific. The system gradually organized, and it was classified as a tropical depression on October 4. On the next day, the JMA upgraded the storm to a tropical storm and named it Chan-hom. On October 7, the system was upgraded by the JMA into a typhoon. The JMA issued their final warning on the system on October 12 at 00:45 UTC. The JTWC later followed, issuing their final warning on the system at 09:00 UTC. The JMA, however, still tracked Chan-hom as a tropical depression until it was last noted on October 16.

Tropical Storm Linfa
On October 9, the JTWC began tracking a tropical system east-southeast of Da Nang, Vietnam. On October 10, the system was declared as a tropical depression by the JTWC and the JMA. Later that day, the JMA upgraded the system into a tropical storm and named it Linfa. The system continued westward, making landfall on October 11 at 03:00 UTC in Vietnam. The JTWC issued their final warning on the system at 09:00 UTC that day. The JMA later followed, issuing their final warning on the system at 18:00 UTC.

Linfa brought historic amounts of rainfall to Central Vietnam, peaking at 90.16 inches (2,290 mm) in A Lưới (Huế), 59.842 inches (1,520 mm) in Hướng Linh (Quảng Trị). That made it the 12th wettest tropical cyclone in history. At least 370,000 people in Vietnam lost power after the storm. So far the storm and its flood have left 104 people dead and 38 remain missing in Vietnam and Cambodia. In Cambodia, severe flooding affected 16 provinces including Phnom Penh, killed at least 21 people, damaged over 25,000 homes over and over 180,000 hectares of farmland.

Tropical Storm Nangka (Nika)
On October 11, the JMA began tracking a tropical depression off the west coast of Luzon. The PAGASA declared the system as a tropical depression at 12:00 UTC, and since the storm formed inside of the Philippine Area of Responsibility (PAR) the agency named the system Nika. On the same day at 21:00, the JTWC began issuing warnings on the system. On October 12, the system was declared a tropical storm by the JMA, and was named Nangka. At 09:00 UTC, the system left the PAR and the PAGASA issued its final bulletin on the system. At 19:20 CST (11:20 UTC) on October 13, Nangka made landfall over Qionghai, Hainan.

On October 13, the storm crossed the Gulf of Tonkin and made landfall in the Nam Định, Ninh Bình, and Thanh Hóa provinces in Northern Vietnam on October 14. On the same day, both the JMA and JTWC issued their final warnings for the system. The system dissipated on October 14, 2020.

After the passage of Nangka over Hainan Island, 2 people died and 4 are missing as a result of a capsized boat. In Northern Vietnam, the storm killed 2 people in Hòa Bình, another missing in Yên Bái. Over 585 houses were destroyed, while 135,731 others across central Vietnam were flooded.

Tropical Depression Ofel
A low pressure area formed in the Philippine Sea, east of Leyte, on October 13. Soon, the PAGASA declared the newly formed system as a tropical depression and assigned it the name Ofel. The PAGASA immediately raised warning signals for the province of Sorsogon and for parts of the Samar province. On the same day at 18:30 UTC, Ofel made landfall over Can-avid, Eastern Samar. As the system entered the West Philippine Sea in the early hours of October 15 UTC, the PAGASA lifted all tropical cyclone warning signals for Ofel. On the same day at 20:00 UTC, Ofel left the Philippine Area of Responsibility (PAR) and PAGASA issued their final bulletin for the system. While Ofel was inside the PAR, the Joint Typhoon Warning Center issued tropical cyclone formation alerts for the system, however it was canceled as the system entered a less favorable environment on October 16. The storm dissipated at 03:00 UTC on that day.

Flooding was reported due to moderate to heavy rains. According to the Department of Agriculture Regional Office 5, total damages have topped to an estimated ₱9.1 million (US$187,000).

Typhoon Saudel (Pepito)
On October 16 UTC, the JTWC began tracking an area of convection approximately 463 nmi east-southeast of Palau. On October 18 at 21:00 UTC, the PAGASA upgraded the system into a tropical depression, and named the system Pepito. A few hours later, the JMA also recognized the system into a tropical depression, and subsequently issued their first warning on the system. As the system intensified as it approached Northern Luzon, the JMA upgraded the system into a tropical storm and named the system Saudel. The PAGASA also declared the system as a tropical storm, and began issuing Signal #2 tropical cyclone warnings in preparation for its landfall. Saudel made landfall over the San Ildefonso Peninsula in Casiguran, Aurora on October 20 at 13:00 UTC (21:00 PHT) and began crossing the Luzon Island, emerging over the West Philippine Sea hours later. As the storm left the Philippine Area of Responsibility, the developing severe tropical storm was upgraded into a typhoon by the JMA, the JTWC, and by the PAGASA in their final bulletin for the system.

As of October 24, the NDRRMC reported total damages of about ₱105.8 million (US$2.18 million).

Tropical Depression 20W
On October 19, the JTWC began tracking a tropical disturbance 160 nmi west of Iwo To. This disturbance strengthened while tracking north, and was eventually upgraded into a tropical depression by the JTWC. The system continued to follow a slightly erratic track in the Pacific Ocean at the south of Japan until it entered an unfavorable environment for development due to strong vertical wind shear, which caused the system to quickly weaken until it dissipated on October 23.

Typhoon Molave (Quinta)
On October 23, the JMA began tracking a tropical depression approximately 190 nmi north of Palau. On the same day, PAGASA followed suit as the system formed inside of the Philippine Area of Responsibility (PAR), east of Mindanao, and named the system Quinta. On October 24, the JTWC also recognized the system as a tropical depression. At 15:00 of the same day, the JTWC upgraded the system into a tropical storm, with the JMA and PAGASA doing the same a few hours apart from each other. Now a tropical storm, the system was named Molave by the JMA. On October 25, PAGASA upgraded the system into a severe tropical storm as it tracked closer to the Bicol Region. Later that day, the PAGASA then upgraded Molave into a typhoon as it headed for Albay and Camarines Sur, prompting the raising of Signal #3 tropical cyclone warnings for both and adjacent provinces. Moments later, the JMA also upgraded the system to a typhoon and the JTWC followed a few hours later. At 18:10 PHT (10:10 UTC), Molave made its first landfall on the San Miguel Island in Albay, with another in Malinao just 40 minutes later. Molave made a total of 5 landfalls in the Luzon area before entering the West Philippine Sea on October 26. On October 27 at 00:00 UTC, Molave left the PAR, with PAGASA issuing their last bulletin for the system later at 15:00. After that, Typhoon Molave intensified even more and peaked as a Category 3 major typhoon in the South China Sea.

, the NDRRMC reported that 27 people were killed, 40 people were injured and four went missing after the typhoon. Damage from infrastructure and agriculture counted to be ₱1.56 billion (US$32.2 million) and ₱2.66 billion (US$54.9 million) respectively, with a total damage of ₱4.22 billion (US$87.1 million) nationwide. In Vietnam, Molave left 41 dead, 143 were injured and 42 people missing. Economic losses were estimated to be 12.92 trillion dong (US$558 million).

Typhoon Goni (Rolly)
After Typhoon Molave devastated the Philippines, the JMA announced the formation of a new tropical depression in the Pacific Ocean, west of the Mariana Islands, on October 27. By the next day, the JTWC had also followed and upgraded the system into a tropical depression. As the system continued tracking westward under favorable conditions in the Pacific Ocean, the JMA and JTWC upgraded the system into a tropical storm, with the JMA assigning the name Goni to the intensifying storm. Due to the warm waters surrounding the storm, the system underwent rapid intensification and became a typhoon. On October 29, at 9:30 UTC, Goni entered the Philippine Area of Responsibility (PAR) and was named Rolly by the PAGASA. By 18:00 UTC, Goni had intensified into a Category 4-equivalent typhoon, with 1-minute sustained winds at 120 kn, and eventually the first Category 5-equivalent typhoon of the season a few hours later. Warm sea surface temperatures, low vertical wind shear and high ocean heat content continually supported Goni as it edged closer to the Philippines, and it maintained its intensity into the next day. At 18:00 UTC October 31 (2:00 PST November 1), PAGASA upgraded Goni to a super typhoon on the agency's tropical cyclone intensity scale at which time the JMA and PAGASA both reported 10-minute sustained winds of 220 km/h (140 mph) and 225 km/h, respectively, marking the second time Tropical Cyclone Wind Signal #5 was raised by PAGASA since Typhoon Haima in 2016. Goni made its first two landfalls at peak intensity over Bato, Catanduanes (20:50 UTC) and Tiwi, Albay (23:20 UTC). After that, it weakened into a strong typhoon and made a third landfall in San Narciso, Quezon. Due to three landfalls, Goni lost its immense strength and weakened into a minimal typhoon as it made a fourth landfall in San Juan, Batangas. Before exiting the PAR, Goni slightly intensified, but further development was hampered by unfavorable conditions. The capital, Manila, experienced some tropical storm-force winds from Goni.

, the NDRRMC has reported ₱12.9 billion (US$266 million) of infrastructure damages, along with ₱5 billion (US$103 million) of agricultural damage, with a combined total of ₱17.9 billion (US$369 million), and at least 25 deaths, 399 injured and 6 missing. Goni is estimated to have caused at least ₱48.058 billion (US$1.04 billion) in damages in the Philippines.

Severe Tropical Storm Atsani (Siony)
On October 28, the JTWC began tracking a new tropical disturbance 95 nmi south-southwest of Chuuk in the Federated States of Micronesia. This disturbance would eventually strengthen into a new tropical depression in the early hours of October 29. Later that day, the JMA upgraded the system into a tropical storm. On November 1, at 00:00 UTC, Atsani entered the PAGASA's Philippine Area of Responsibility (PAR), with the PAGASA naming the system Siony. The storm tracked northwest through the Philippine Sea, passing through the Luzon Strait on November 4. The system left the PAR on November 7 at 21:00 UTC. Shortly afterwards, the system rapidly weakened and dissipated thereafter.

Atsani downed trees, caused landslides, and damaged street lights in parts of Taiwan. Rockfalls caused some roads to close in Taitung County. 3 minor injuries were reported within Taitung County in the townships of Haiduan and Jinfeng. The storm brought heavy rains to Batanes and the Babuyan Islands in the Philippines, causing ₱4.9 million (US$101 thousand) in agricultural damage.

Tropical Storm Etau (Tonyo)
On November 7, the Japan Meteorological Agency (JMA) began tracking a tropical depression 460 nmi east-southeast of Manila. At 12:00 UTC on the same day, the PAGASA declared the system as a tropical depression and assigned it the name Tonyo, as it formed directly over Burias Island. The Joint Typhoon Warning Center recognized the system as a tropical depression at 15:00 UTC on November 8. Etau caused rains over Calabarzon, Mimaropa, and the Bicol Region before exiting the Philippine Area of Responsibility on November 9 at 21:00 UTC. It continued its way towards Vietnam, after crossing Philippines.

Etau killed two people in Quảng Nam and Bình Định and damaged 400 houses when it made landfall in central Vietnam on November 10. The storm produced over 250 mm (10 in) of rain in the provinces of Bình Định, Khánh Hòa, and Phú Yên, with peak at 858 mm in Lake Thủy Yên (Thừa Thiên Huế). The storm also caused gusty winds which uprooted trees and ripped roofs of buildings, many of which were still recovering from the adverse impacts of Typhoon Molave and the weakened Tropical Storm Goni. In addition, power outages locally affected the city of Tuy Hòa. Economic losses in Tuy An, Phú Yên were counted as 122 billion VND (US$5.26 million).

Typhoon Vamco (Ulysses)
On November 8, the JMA began tracking a new tropical depression 132 nmi north-northwest of Palau. At 12:00 UTC on the same day, the PAGASA declared the system as a tropical depression inside of the Philippine Area of Responsibility and named it Ulysses. The next day at 7:15 UTC, the system strengthened into a tropical storm, with the JMA giving it the name Vamco, with the Joint Typhoon Warning Center later issuing their first warning on the system as a tropical depression. As the system tracked closer to southern Luzon, both the PAGASA and the JMA upgraded Vamco into a severe tropical storm. Vamco was then upgraded into typhoon status by the JMA on November 11, followed by the JTWC and the PAGASA shortly after, as the PAGASA raised Signal #3 tropical cyclone wind signals in preparation for the storm. At 14:30 UTC and 15:20 UTC, Vamco made its first two landfalls over the island towns of Patnanungan and Burdeos, respectively, both in Quezon Province. Later at 17:40 UTC, Vamco made its third landfall over General Nakar, Quezon, in the Luzon landmass. At 00:00 UTC, the system emerged over the western seaboard of Zambales and entered the West Philippine Sea. The system left the PAR at 01:30 UTC as the PAGASA redeclared the system as a typhoon. Vamco rapidly re-strengthened in the South China Sea and peaked as a Category 4-equivalent typhoon briefly before weakening back into a Category 3-equivalent storm heading for Vietnam. The typhoon then weakened before making another landfall as a Category 1-equivalent typhoon in Vietnam.

As of 08:00 PHT on December 10, 2020, the NDRRMC reported a total of 196 casualties (Iincluding 101 validated deaths, 85 injuries and 10 missing) caused by the typhoon, along with   worth of agriculture damages and   worth of infrastructural damages. The Cagayan Valley experienced the highest total amount of damage. At least 3,052,049 individuals were affected by the typhoon's onslaught. The Armed Forces of the Philippines and Philippine National Police reportedly rescued 265,339 and 104,850 individuals, respectively. According to Aon, total economic losses caused by the typhoon were estimated to top.

Tropical Storm Krovanh (Vicky)
On December 17 at 21:00 UTC, the PAGASA began issuing bulletins for a system 140 nmi east-southeast of Davao. The PAGASA had already recognized the system as a tropical depression and named it Vicky, however at the time, the Japan Meteorological Agency (JMA) only recognized the system as a low-pressure area. The next day, the JMA followed suit and recognized the system as a tropical depression. At 14:00 PHT (6:00 UTC), the system made landfall in Baganga, Davao Oriental. 9 hours later, it emerged off the coast of Misamis Oriental and entered the Bohol Sea, later entering the Sulu Sea on the next day at 5:00 PHT (23:00 UTC). On December 19 at 23:00 PHT (15:00 UTC), Krovanh made its second landfall over central Palawan, emerging into the West Philippine Sea shortly after. As the storm traversed the South China Sea, the system had strengthed into a tropical storm according to the JMA as it emerged into a region of relatively favorable atmospheric conditions, thus given the name Krovanh. On December 20 at 14:00 PHT (6:00 UTC), Krovanh left the Philippine Area of Responsibility, although storm signals were still raised for the Kalayaan Islands. The PAGASA then upgraded Krovanh into a tropical storm, and issued a Signal No. 2 warning for the Kalayaan Islands. The next day, December 21, Krovanh was downgraded into a tropical depression by both the JMA and by the PAGASA in their final advisories for the storm. The JTWC then issued their final warning on Krovanh the next day shortly after most of its central convection had dissipated due to increasingly hostile wind shear.

Large swaths of Visayas and Mindanao were placed under Signal No. 1 warnings due to Krovanh. Floods and landslides were triggered in Cebu, Agusan del Sur, Davao de Oro, and in Leyte, where two senior citizens were killed in a landslide. In Lapu-Lapu City, 300 residents were forced to evacuate after 76 houses near the shore were swept into sea. Around 6,702 individuals were affected by the storm in the Philippines, with 5,646 in evacuation centers. Damages have been estimated to total up to ₱213.2 million (US$4.48 million). At least eight people were killed by the effects of Krovanh.

Other systems
Late on July 27, the JMA began to track a weak tropical depression in the open Western Pacific. Later on the following day, the system was unofficially classified as a subtropical depression by the JTWC, when it has been given a low-chance of transitioning to a tropical cyclone. On a marginal environment with cyclonic easterly flow, moderate to strong wind shear and 28–30 °C sea surface temperatures, the system was expected to recurve poleward and be absorbed by a larger extratropical low. The depression, however, dissipated on July 30.

The JMA began monitoring on another tropical depression to the south of Japan on September 27. The system moved in a general northeastward direction until it was last noted on 18:00 UTC on September 29.

On October 7, the Vietnam Center for Hydro-Meteorological Forecasting (VNCHF) monitored a tropical depression that had made landfall in the Khánh Hòa province. Enhanced by the seasonal northeast monsoon, the system caused many provinces nearby to experience heavy rainfall with average accumulations of 200–300 mm. In Sa Huỳnh (Quảng Ngãi), rainfalls peaked at 360 mm. By October 11, heavy floods killed 9 people.

On December 5, a tropical depression formed to the south of Japan. The depression was short-lived, however, as it dissipated the next day after being embedded into a frontal zone.

On December 29, the JMA started to track a weak tropical depression to the east of Vietnam.

Super Cyclonic Storm Amphan
At 00:00 UTC on May 16, a depression formed in the southeast Bay of Bengal and was identified as BOB 01. Six hours later, the Indian Meteorological Department (IMD) upgraded the system to a deep depression. The system began bringing torrential rainfall to Sri Lanka and Southern India. Around 15:00 UTC, the system further developed into Cyclonic Storm Amphan. That morning, landslide and flooding warnings were hoisted for parts of eastern Sri Lanka and the Indian state of Kerala were given expectations of torrential rainfall in the coming days. By 09:00 UTC on May 17, Amphan had intensified into a very severe cyclonic storm. Within 12 hours, the storm had developed an eye and started to rapidly intensify, becoming an extremely severe cyclonic storm. According to the JTWC, it explosively intensified from a Category 1-equivalent cyclone to a Category 4-equivalent cyclone in just 6 hours. The following morning around 10:30 UTC, the IMD upgraded Amphan to a super cyclonic storm with 3-minute sustained winds of 240 km/h (150 mph) and a minimum pressure of 920 hPa (27.46 inHg). This marked the second year in a row featuring a super cyclonic storm, the previous year seeing Kyarr in the Arabian Sea. On May 20, at approximately 17:30 IST, the cyclone made landfall near Bakkhali, West Bengal after weakening subsequently. It rapidly weakened once inland, and dissipated on the next day. It left behind a trail of catastrophic damage, and was later confirmed to be the costliest storm ever recorded in the basin.

Depression ARB 01
A depression formed overland near Salalah, Oman on May 29.

The Public Authority for Civil Aviation (PACA) in Oman advised residents to exercise caution and not to venture to low-lying areas or sea. The Supreme Committee asked people to remain at home in non-emergency circumstances. The hospital in Sadah was evacuated as the depression intensified. Over 200 mm of rain fell in Dhofar Governorate on May 29; some areas received the equivalent of 2 years of rainfall. The highest precipitation total was measured in Mirbat, where 1055 mm of rain fell. 2 days of heavy rainfall, accumulating to 260 mm, caused floods in Salalah. Operations at the port of Salalah were interrupted by the tropical depression. Residents in central Salalah experienced disruptions to power and water services. Military police were dispatched to clear roads and airlift people marooned by the floods. Engineering teams from the Ministry of Defence were deployed to restore utilities and render air where necessary. 2 people were found dead in a wadi due to flash floods, while another person died and three were injured when a building collapsed. More than 50 people were rescued from floods.

Severe Cyclonic Storm Nisarga
During May 31, an area of low pressure developed over the south-eastern Arabian Sea and remained as a well marked low pressure area over the same region until the evening. It strengthened into a depression over the east-central and south-east Arabian Sea in the early morning of June 1 when it was centered about 340 km south-west of Goa, 630 km south-southwest of Mumbai and 850 km south-southwest of Gujarat. It gave nearly 400 mm of extremely heavy rain at Kavaratti, Lakshadweep. On June 2, around noon, the prevailing deep depression intensified into a cyclonic storm thereby receiving the name Nisarga. The name has been contributed by Bangladesh. Nisarga intensified into a severe cyclonic storm before making landfall near the coastal town of Alibag in Maharashtra at 12:30 (IST) on June 3. At the time, the system was at peak intensity with 3-minute sustained winds of 110 km/h (70 mph) and a central pressure of 984 hPa (29.06 inHg). The cyclone subsequently weakened into a deep depression by June 4.

Deep Depression BOB 02
After 3 months of inactivity, on October 11, a depression developed over the west-central Bay of Bengal, though the system was originally observed near the Spratly Islands over the South China Sea on October 6. It continued to move westwards, making landfall in the Khánh Hòa province and further weakened into a low pressure cell while crossing the Indochina Peninsula and re-emerged in the Andaman Sea on October 9. It intensified into a well-marked low pressure area and then into a depression over the Bay of Bengal on October 10. It further intensified into a deep depression on October 12, remaining practically stationary over the same region. After that, BOB 02 moved west-northwestwards and made landfall in Andhra Pradesh near Kakinada in the early hours of October 13 and weakened again into a depression.

Due to BOB 02, Yanam (Puducherry), Andhra Pradesh, Telengana, Kerala, Maharashtra, and coastal Karnataka experienced heavy rain on October 12 and 13, with Hyderabad experiencing 32 cm of record-breaking torrential rain, creating flash floods in the city by October 13. At least 50 people died in different parts of Telengana (of which at least 19 were in the capital city of Hyderabad), 10 in Andhra Pradesh, and 38 in Maharashtra. Extreme crop loss in north Karnataka, Andhra Pradesh and Telengana occurred due to the system. The Telengana PM estimated damage costs to be ₹1,305 crore (US$682 million). The system weakened into a well-marked low pressure area in south-central Maharashtra on the evening of October 14. Though the system's lower-level circulation was partially exposed due to high vertical wind shear and continuous land interaction, the JTWC re-issued a tropical cyclone advisory on October 15. The IMD also forecasted BOB 02 to reintensify in the Arabian Sea. The low pressure area intensified into Depression ARB 03 on the early hours of October 17.

The system delayed the withdrawal of the southwest monsoon season by almost a week, a delay compounded by the formation of Depression ARB 03 and Depression BOB 03.

Depression ARB 03
On October 17, the remnants of Deep Depression BOB 02 intensified into a depression in the East Central Arabian Sea. Moving westwards, the system dissipated into a well marked low pressure on the morning of October 19 over the West Central Arabian Sea due to unfavorable atmospheric conditions. Fishermen were advised not to go out to sea due to very rough sea conditions. Heavy rainfall occurred off the coast of Mumbai and its surroundings due to the system. No warnings were issued by IMD as no landfall occurred in the Arabian Peninsula.

Monsoon withdrawal was delayed in Maharashtra by a week due to ARB 03.

Depression BOB 03
On October 20, a low pressure formed over Central Bay of Bengal. The system then became more well-marked on October 21 over West Central Bay of Bengal. It further intensified into depression over northwest Bay of Bengal and adjoining Odisha Coast. The system crossed West Bengal's North 24 Parganas and South 24 Parganas and moved over the adjoining Bangladeshi coast on the noon of October 23 with the maximum wind speed of 45 km/h (30 mph). The system weakened into a well marked low pressure area, 50 km north-northwest of Dhaka on the morning of October 24.

Very Severe Cyclonic Storm Gati
On 17 November 2020, the India Meteorological Department (IMD) noted the potential for tropical cyclogenesis over the central Arabian Sea in association with an area convection near the Maldives. Convective activity was enhanced by the Madden–Julian oscillation while sea surface temperatures of 29 to 30 C and low wind shear favored additional development. By 18 November, a weak low-level circulation developed about 1,185 km (735 mi) east-southeast of Socotra. Organization thereafter was stymied as it became embedded within a monsoon trough. Two additional circulations developed to the east and west of the original low; however, the original low steadily became the dominant system by absorbing the previous two circulations. On 21 November, two scatterometer passes revealed a single, well-defined low with gale-force winds underneath an area of flaring convection. At 18:00 UTC, the IMD classified the system as Depression ARB 04 about 410 km (255 mi) east-southeast of Socotra. Similarly, the Joint Typhoon Warning Center (JTWC) initiated advisories on the system as Tropical Cyclone 03A. Steered west by a subtropical ridge to the north, little intensification was expected before the cyclone's forecast landfall in Somalia.

During the overnight of 21 to 22 November the small cyclone quickly organized, with a well-defined eye developing. The IMD upgraded the system to a Deep Depression early on 21 November and a Cyclonic Storm soon after. Upon becoming a cyclonic storm, it was assigned the name Gati. Classified as a "midget system" by the JTWC with a core diameter of only 120 km (70 mi) and a 27 km (17 mi) wide eye, Gati explosively intensified that morning. Within a 12-hour period, the JTWC estimated one-minute sustained winds to have increased from 65 km/h (40 mph) to a peak of 185 km/h (115 mph). This was the fastest intensification during such a short period ever observed in the North Indian Ocean basin. The system's small size enabled it to take advantage of low wind shear and high sea surface temperatures. The IMD assessed Gati to have reached its peak intensity as a Very Severe Cyclonic Storm around 12:00 UTC, with three-minute sustained winds of 140 km/h (85 mph) and a minimum pressure of 976 mbar. Six hours later, Gati had made landfall near Hafun in northeastern Somalia with estimated one-minute sustained winds of 165 km/h (105 mph). This made Gati the first hurricane-force cyclone to strike the country since reliable records began and by default the nation's strongest.

Once onshore, land friction-based shear caused convection to quickly become displaced from the storm's center. The low-level circulation became completely exposed early on 23 November as it traversed northeastern Somalia; the system's upper-level circulation and associated convection detached and accelerated west ahead of the surface low. The increasingly elongated circulation of Gati emerged over the Gulf of Aden by 12:00 UTC, and the JTWC issued their final advisory on the system shortly thereafter.

Very Severe Cyclonic Storm Nivar
On November 22, an area of low pressure was formed in the Bay of Bengal, off the coast of Tamil Nadu. On the same day, the JTWC issued a Tropical Cyclone Formation Alert on the disturbance. It intensified into a depression on the early hours of November 23, as the JTWC also cited that the disturbance intensified into a tropical storm, designating it as Tropical Cyclone 04B. Early on November 24, it intensified into a cyclonic storm and it was named Nivar. It gradually intensified into a Very Severe Cyclonic Storm, reaching its peak intensity. Due to the wind shear, it weakened to a Severe cyclonic storm, shortly before making landfall between Karaikal and Mamallapuram around Puducherry, Wednesday evening. It reemerged on the Bay of Bengal as a strong deep depression before making its last landfall at Andhra Pradesh before weakening to a well marked low pressure on the morning of November 27. The name Nivar was contributed by Iran which means light.

The IMD issued cyclone warnings early on November 24 on Tamil Nadu, Pondicherry and the country of Sri Lanka as the cyclonic storm accelerates and intensifies.

Cyclonic Storm Burevi
On November 28, a low pressure area formed off the coast of Aceh. It gradually intensified into a depression on November 30. The JTWC then issued a Tropical Cyclone Formation Alert on the system, that same day. At 03:00 UTC on December 1, the depression was upgraded into a deep depression. At 15:00 UTC, both the IMD and JTWC upgraded it to a cyclonic storm and tropical storm respectively and it was named Burevi, the fifth named storm of the season. The name was initially suggested by the Maldives. At this time, microwave imagery showed well-defined convective banding wrapping tightly around the low-level circulation (LLCC). At 15:00 UTC on December 2, Burevi reached its peak intensity with 1-minute sustained winds of around 85 km/h (50 mph) and a barometric pressure of 996 mbar (29.41 inHg). Shortly afterwards, Burevi made landfall along the east coast of Sri Lanka according to the Sri Lanka's Department of Meteorology.

After weakening over Sri Lanka, Burevi exited into the Gulf of Mannar, early on December 3. However, Burevi slowed down quickly as it became stuck in a col between two subtropical ridges on December 4; thus it stalled just west of Sri Lanka while it weakened back down to the equivalent of a tropical depression due to increasing vertical wind shear. At 06:00 UTC on December 5, Burevi degenerated into an area of low pressure according to the IMD.

Subtropical Storm Kurumí
On January 21, 2020, the Brazilian Navy Hydrographic Center began to monitor an area of persisting thunderstorms near São Paulo for potential subtropical cyclone development. Generally tracking southeastward, the system began to organize within the afternoon hours of January 22 and was designated a subtropical depression in the early hours of January 23. Several hours later, due to a lack of wind shear, the system intensified into a subtropical storm and was given the name Kurumí. After this bout of intensification, Kurumí moved southward and began to succumb to much more unfavorable conditions. It weakened back to a subtropical depression on January 25, while also beginning to merge with a large extratropical low to its south. The last advisory was issued on Kurumí later that same day.

The front associated with Kurumí later played a role in the 2020 Brazilian floods and mudslides, dragging behind it heavy rainfall. Over 171.8 mm (6.76 in) of rain fell in the Belo Horizonte metro area on January 24, triggering a landslide and killing 3 people and leaving 1 missing.

Subtropical Storm Mani
According to the Hydrographic Center of the Brazilian Navy, on October 25, 2020, a subtropical depression formed off the coast border between Espírito Santo and Bahia, at 00:00 UTC it was named Mani. On October 28, Mani weakened to a low pressure area.

Subtropical Storm Oquira
According to the Hydrographic Center of the Brazilian Navy, late on December 27, a subtropical depression formed off the coast east of Rio Grande do Sul. Moving southwestward, the system's central pressure dropped to 1010 mbar by 00:00 UTC on December 28. Later that day, the system's winds intensified, and it was named Oquira by the Brazilian Hydrographic Center. On December 29, Oquira continued to strengthen, deepening while heading further southwestward away from the Brazilian mainland, and reaching a pressure of 1002 mbar. Afterward, Oquira's winds decreased and the storm weakened to a subtropical depression on December 30, but the storm's pressure continued to drop, bottoming out at a minimum central pressure of 998 hPa (29.47 inHg). On December 31, Oquira transitioned into an extratropical low, and the Hydrographic Center issued their final advisory on the storm.