Talk:2020 Atlantic hurricane season/Link Archiver/1

The 2020 Atlantic hurricane season is an ongoing tropical cyclone season which has featured tropical cyclone formation at a record-breaking rate. So far, there have been a total of 27 tropical or subtropical cyclones, 26 named storms, 10 hurricanes, and 4 major hurricanes. With 26 named storms, it is the second most active Atlantic hurricane season on record, behind only the 2005 Atlantic hurricane season. It is also only the second tropical cyclone season to feature the Greek letter storm naming system, with the other season also being 2005. The season officially started on June 1 and will officially end on November 30; however, formation of tropical cyclones is possible at any time, as illustrated by the formations of tropical storms Arthur and Bertha, on May 16 and 27, respectively. This marked the record sixth consecutive year with pre-season systems. During the season, Tropical Storm Cristobal and 22 later systems have broken the record for the earliest formation by storm number. Of the 26 named storms, 10 made landfall in the contiguous United States, breaking the record of nine set in 1916. In addition, the season is the first to see seven named tropical cyclones make landfall in the continental United States before September. This activity has been fueled by an ongoing La Niña, which developed during the summer months of 2020.

In early June, Cristobal caused 15 deaths and $665 million in damage across Mexico, Guatemala, and the United States. In July, Fay brought gusty winds across Delaware, New Jersey, and Coastal New York, resulting in $350 million in damage and six deaths. Hanna, the season's first hurricane, made landfall in South Texas as a Category 1, leaving at least $875 million in damage. Isaias, the second hurricane of the season, made landfall in The Bahamas and North Carolina, both times as a Category 1 hurricane, and brought widespread power outages and a destructive tornado outbreak to the Eastern United States, causing an overall $4.725 billion in damage.

In August, Laura became the strongest tropical cyclone on record in terms of wind speed to make landfall in Louisiana, alongside the 1856 Last Island hurricane. Overall, Laura caused at least $14.1 billion in damage and 77 deaths. September was the most active month on record in the Atlantic, with ten named storms. Hurricane Nana impacted Central America, destroying many acres of banana crop. Later, Hurricane Paulette made landfall in Bermuda, while Hurricane Sally severely impacted the Southeastern United States. A massive Hurricane Teddy made its way to Atlantic Canada, making landfall as an extratropical cyclone, while also becoming the fourth largest tropical cyclone by gale-force winds on record. By mid-September, the active Atlantic spawned a brief subtropical storm, Alpha, that made an unprecedented landfall in Portugal after becoming the easternmost-forming (sub)tropical cyclone in the North Atlantic basin on record. Tropical Storm Beta formed in the Gulf of Mexico, affecting Texas and Louisiana. With 10 (sub)tropical storms, September 2020 was the most active month on record.

In October, Gamma struck Mexico's Yucatán Peninsula. Hurricane Delta then impacted a large swath of the Western Caribbean while also becoming the season's third major hurricane. Delta made landfall in the Yucatán and then in Louisiana, becoming the 10th storm to strike the continental U.S. this season. Hurricane Epsilon formed in mid-October southeast of Bermuda and grew into the season's 4th major hurricane.

Early on, officials in the United States expressed concerns the hurricane season could potentially exacerbate the effects of the COVID-19 pandemic for U.S. coastal residents. As expressed in an op-ed of the Journal of the American Medical Association, "there exists an inherent incompatibility between strategies for population protection from hurricane hazards: evacuation and sheltering (i.e., transporting and gathering people together in groups)," and "effective approaches to slow the spread of COVID-19: physical distancing and stay-at-home orders (i.e., separating and keeping people apart)."

Seasonal forecasts
Forecasts of hurricane activity are issued before each hurricane season by noted hurricane experts, such as Philip J. Klotzbach and his associates at Colorado State University, and separately by NOAA forecasters.

Klotzbach's team (formerly led by William M. Gray) defined the average (1981 to 2010) hurricane season as featuring 12.1 tropical storms, 6.4 hurricanes, 2.7 major hurricanes (storms reaching at least Category 3 strength in the Saffir–Simpson scale), and an accumulated cyclone energy (ACE) index of 106 units. NOAA defines a season as above normal, near normal or below normal by a combination of the number of named storms, the number reaching hurricane strength, the number reaching major hurricane strength, and the ACE Index.

Pre-season forecasts
On December 19, 2019, Tropical Storm Risk (TSR), a public consortium consisting of experts on insurance, risk management, and seasonal climate forecasting at University College London, issued an extended-range forecast predicting a slightly above-average hurricane season. In its report, the organization called for 15 named storms, 7 hurricanes, 4 major hurricanes, and an ACE index of 105 units. This forecast was based on the prediction of near-average trade winds and slightly warmer than normal sea surface temperatures (SSTs) across the tropical Atlantic as well as a neutral El Niño–Southern Oscillation (ENSO) phase in the equatorial Pacific. On April 2, 2020, forecasters at Colorado State University echoed predictions of an above-average season, forecasting 16 named storms, 8 hurricanes, 4 major hurricanes, and an ACE index of 150 units. The organization posted significantly heightened probabilities for hurricanes tracking through the Caribbean and hurricanes striking the U.S. coastline. TSR updated their forecast on April 7, predicting 16 named storms, 8 hurricanes, 3 major hurricanes, and an ACE index of 130 units. On April 13, the University of Arizona (UA) predicted a potentially hyperactive hurricane season: 19 named storms, 10 hurricanes, 5 major hurricanes, and accumulated cyclone energy index of 163 units. A similar prediction of 18 named storms, 9 hurricanes, and 4 major hurricanes was released by The Weather Company on April 15. Following that, North Carolina State University released a similar forecast on April 17, also calling for a possibly hyperactive season with 18–22 named storms, 8–11 hurricanes and 3–5 major hurricanes. On April 21 the Pennsylvania State University Earth Science System Center also predicted high numbers, 19.8 +/- total named storms, range 15-24, best estimate 20.

On May 20, Mexico's Servicio Meteorológico Nacional released their forecast for an above-average season with 15–19 named storms, 7–9 hurricanes and 3–4 major hurricanes. The UK Met Office released their outlook that same day, predicting average activity with 13 tropical storms, 7 hurricanes, and 3 major hurricanes expected to develop between June and November 2020. They also predicted an ACE index of around 110 units. NOAA issued their forecast on May 21, calling for a 60% chance of an above-normal season with 13–19 named storms, 6–10 hurricanes, 3–6 major hurricanes, and an ACE index between 110% and 190% of the median. They cited the ongoing warm phase of the Atlantic multidecadal oscillation and the expectation of continued ENSO-neutral or even La Niña conditions during the peak of the season as factors that would increase activity.

Mid-season forecasts
On June 4, Colorado State University released an updated forecast, calling for 19 named storms, 9 hurricanes, and 4 major hurricanes. On July 7, Colorado State University released another updated forecast, calling for 20 named storms, 9 hurricanes, and 4 major hurricanes. On July 7, Tropical Storm Risk released an updated forecast, calling for 18 named storms, 8 hurricanes, and 4 major hurricanes. On July 16, The Weather Company released an updated forecast, calling for 20 named storms, 8 hurricanes, and 4 major hurricanes.

On August 5, Colorado State University released an additional updated forecast, their final for 2020, calling for a near-record-breaking season, predicting a total of 24 named storms, 12 hurricanes, and 5 major hurricanes, citing the anomalously low wind shear and surface pressures across the basin during the month of July and substantially warmer than average tropical Atlantic and developing La Niña conditions. On August 5, Tropical Storm Risk released an updated forecast, their final for 2020, also calling for a near-record-breaking season, predicting a total of 24 named storms, 10 hurricanes, and 4 major hurricanes, citing the favorable July trade winds, low wind shear, warmer than average tropical Atlantic, and the anticipated La Niña. The following day, NOAA released their second forecast for the season whilst calling for an "extremely active" season containing 19–25 named storms, 7–11 hurricanes, and 3–6 major hurricanes. This was one of the most active forecasts ever released by NOAA for an Atlantic hurricane season.

Seasonal summary
Tropical cyclogenesis began in the month of May, with tropical storms Arthur and Bertha. This marked the first occurrence of two pre-season tropical storms in the Atlantic since 2016, the first occurrence of two named storms in the month of May since 2012, and the record sixth consecutive season with pre-season activity, extending the record set from 2015 to 2019. Tropical Storm Cristobal formed on June 1, coinciding with the official start of the Atlantic hurricane season, also making Cristobal the earliest-named third storm on record in the Atlantic basin. Tropical Storm Dolly also formed in June. Tropical storms Edouard, Fay, and Gonzalo, along with hurricanes Hanna and Isaias, formed in July. Hanna became the first hurricane of the season and struck South Texas, while Isaias became the second hurricane of the season and struck much of the Caribbean and the East Coast of the United States. Tropical Depression Ten also formed in late July off the coast of West Africa, although it did not reach tropical storm status and quickly dissipated. Nonetheless, July 2020 tied 2005 for the most active July on record in the basin in terms of named systems. August saw the formations of tropical storms Josephine and Kyle, and hurricanes Laura and Marco. Marco ultimately became the third hurricane of the season, but rapidly weakened before making landfall in southeast Louisiana. Laura subsequently became the fourth hurricane, and first major hurricane of the season, before making landfall in southwest Louisiana at Category 4 strength with 150 mph (240 km/h) winds. The month concluded with the formation of Tropical Depression Fifteen, which intensified into Tropical Storm Omar on September 1.

September featured the formations of tropical storms Rene, Vicky, Wilfred, and Beta, Subtropical Storm Alpha, and hurricanes Nana, Paulette, Sally, and Teddy. This swarm of storms coincided with the peak of the hurricane season and the development of La Niña conditions. Hurricane Sally made landfall near Miami, Florida as a tropical depression before causing extensive damage throughout the Southeastern United States, as a category 2 hurricane. Teddy, the season's eighth and second major hurricane, initially formed on September 12, while Tropical Storm Vicky formed two days later. With the formation of Vicky, five tropical cyclones were simultaneously active in the Atlantic basin for the first time since 1995. Paulette became the first storm to strike Bermuda since Hurricane Gonzalo in 2014, while Sally struck Gulf Shores, Alabama on the same day and location where Hurricane Ivan made landfall in 2004. Meanwhile, Hurricane Teddy went on to strike Atlantic Canada as an extremely large extratropical cyclone on September 23. Additionally, Paulette briefly reformed as a tropical storm before once again becoming post-tropical. Within a six hour span on September 18, Wilfred, Alpha, and Beta became named systems, an event only previously recorded in 1893. Alpha impacted the Iberian Peninsula, and was the first named storm to make landfall in Portugal. Beta's intensification into a tropical storm made September 2020 the most active month on record with 10 cyclones becoming named. Beta went on to impact Texas, Louisiana, and Mississippi before transitioning into a remnant low over Alabama, marking an abrupt end to the 18 straight days of activity.

After a period of inactivity, Tropical Depression Twenty-Five developed in the western Caribbean Sea on October 2 before further strengthening into Tropical Storm Gamma early the next day and impacting the Yucatan Peninsula the day after that. Early on October 5, Tropical Storm Delta developed in the Caribbean Sea south of Jamaica before becoming the ninth hurricane of the season early the next day. It then impacted a large swath of the Western Caribbean while also becoming the season's third major hurricane. Delta made landfall on the Yucatan Peninsula on October 7 as a Category 2 hurricane, followed by a second landfall in Louisiana on October 9 also as a Category 2 hurricane. After 14 more days of inactivity, Tropical Storm Epsilon formed in mid-October and became the season's 10th hurricane on October 20, making 2020 the 5th Atlantic hurricane season in the satellite era (since 1966) to have at least 10 hurricanes by October 20, in addition to: 1969, 1995, 2005 and 2017.

The 2020 season has featured activity at a record pace. The season's third named storm and all named storms from the fifth onwards have formed on an earlier date in the year than any other season since reliable records began in 1851. The accumulated cyclone energy (ACE) index for the 2020 Atlantic hurricane season, as of 15:00 UTC October 22, is 125.83 units. Broadly speaking, ACE is a measure of the power of a tropical or subtropical storm multiplied by the length of time it existed. It is only calculated for full advisories on specific tropical and subtropical systems reaching or exceeding wind speeds of 39 mph.

Tropical Storm Arthur
On May 14, The NHC began monitoring an area of disturbed weather which was expected to form just north of Cuba in a couple of days. The interaction of an upper-level trough and a stalled front over the Florida Straits led to the formation of a low-pressure area in that region on May 15. The system moved north-northeast and developed into a tropical depression east of Florida around 18:00 UTC on May 16, before an Air Force reconnaissance aircraft found that it had become Tropical Storm Arthur six hours later. 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. No damage was reported in North Carolina, although gusty winds in the Bahamas damaged temporary tents and shelters which had been set up for Hurricane Dorian relief efforts.

Tropical Storm Bertha
On May 24, a trough of low pressure developed over the southeastern Gulf of Mexico. Widespread convection accompanied the system, though its overall structure remained disorganized as it moved northeast across the Gulf. An increase in convection in the system over Florida developed a distinct low pressure area, but the system remained disorganized as it paralleled the East Coast throughout May 26. However, 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 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. On May 29 Bertha was absorbed by a larger extratropical low over Quebec.

The precursor disturbance to Bertha caused a significant multi-day rainfall event across South Florida, with accumulations of 8 – across several locations, and with a maximum 72-hour accumulation of 14.19 in in Miami. Damage was primarily limited to localized flooding, especially around canals, and an EF1 tornado caused minor damage in southern Miami. Some flash flooding and tree damage occurred near the landfall location in South Carolina, though overall effects from the storm were negligible. One person drowned due to rip currents along the coast of Myrtle Beach. Overall, Bertha caused at least $133,000 in damage.