Cyclones Katrina and Victor–Cindy

Severe Tropical Cyclones Katrina and Victor–Cindy were a long-lived pair of related tropical cyclones, which moved around the coast of northeastern Australia during parts of January and February 1998, before eventually moving into the southern Indian Ocean. Katrina was the fourth tropical cyclone and named storm of the 1997–98 Australian region cyclone season; Victor–Cindy was the seventh tropical cyclone and named storm of the 1997–98 Australian region cyclone season; after moving into the South-West Indian Ocean, Victor–Cindy became the fifth tropical cyclone and the fourth named storm of the 1997–98 South-West Indian Ocean cyclone season. Katrina developed on 1 January and meandered within the Coral Sea between the Queensland coast and Vanuatu for the next three weeks, before degenerating into a remnant low near Far North Queensland on 25 January. After its decay, the remnants of Katrina moved westward over Cape York Peninsula and the Gulf of Carpentaria, before regenerating into Cyclone Victor on February 8, after which the system moved through the Northern Territory and into the Indian Ocean, over the course of the next week. Upon reaching the Indian Ocean on 16 February, the system was named "Cindy" by Mauritius, before eventually dissipating on 19 February.

Cyclone Katrina impacted parts of Queensland, Vanuatu, and the Solomon Islands, killing two people and causing $8.66 million (1998 USD) in damages.

Katrina
On 1 January, the Australian Bureau of Meteorology (BoM) started to monitor a tropical low that had developed within the monsoon trough about 630 km to the east-northeast of Cairns in Queensland, Australia. During that day, the system moved south-eastward, before it entered an area of weak steering flow, which made the system perform a small cyclonic loop over the next two days. Early on 3 January, the United States Joint Typhoon Warning Center (JTWC) initiated advisories on the system and designated it as Tropical Cyclone 12P. This was after the system had rapidly intensified, and a wind report of 57 km/h had been received from Lihou Reef. At about the same time, the BoM named the system Katrina, as it had become a Category 1 tropical cyclone on the Australian tropical cyclone intensity scale. After the system was named, an increase in the deep westerly flow to the north of the system caused Katrina to start moving north-eastward, towards the South Pacific basin. Over the next few days, the system slowly intensified further, as the system's inflow was dominated by Cyclone Susan, which was rapidly intensifying to the west of Vanuatu. Susan's outflow also caused a moderate amount of vertical wind shear over Katrina, which helped to inhibit development of the system and weakened it slightly.

Katrina crossed 160°E and moved into the South Pacific basin during 7 January, where it was monitored by the Fiji Meteorological Service (FMS), as it passed about 90 km to the south of Rennell Island in the Solomon Islands. The system subsequently started move south-eastward towards the island nation of Vanuatu, as started to intensify faster, as Susan moved south-eastward towards Fiji. The system subsequently came within 220 km of Vanuatu's northernmost island, Espiritu Santo, before it recurved westward during 9 January, due to a weakening of the monsoonal westerlies and the development of an anticyclone to the south of the system. Later that day, the FMS reported that the system had peaked as a Category 3 severe tropical cyclone on the Australian region scale, with 10-minute sustained wind speeds of 150 km/h (90 mph). The JTWC also reported during 9 January that the system had peaked with 1-minute sustained wind speeds of 165 km/h (105 mph), which made the system equivalent to a Category 2 hurricane on the Saffir–Simpson hurricane wind scale.

On 11 January, Katrina moved south of Rennell Island and then crossed back into the Brisbane area six hours later, where it crossed the 160E on its eastward journey, then the storm turned westward, where it maintained that course until 15 January. On January 15, the storm moved south-southwestward, where it reached Category 2-equivalent strength on the Saffir–Simpson Hurricane Scale, with a central barometric pressure of 940 mbar. Katrina weakened rapidly and slowed before making a tight loop on 17 and 18 January. After completing the loop, Cyclone Katrina moved eastward for 12 hours, before moving east-southeastward for three days. During that time, Katrina briefly reached Category 1 strength once more, before slowing down and being affected by wind shear. By 24 January, Katrina had weakened to a tropical depression. Over the next few days, Katrina's remnant low moved south-westward, before turning northwestward during 28 January. The system was last noted by the JTWC on 2 February, while situated just off the coast of the Cape York Peninsula.

Victor–Cindy
The tropical low that was to become Severe Tropical Cyclone Victor-Cindy was first noted over Australia's Top End by the BoM on 5 February 1998 and was presumed to have formed out of the remnants of Severe Tropical Cyclone Katrina. Over the next couple of days, the system moved westwards over the Top End under the influence of a subtropical ridge of high pressure and emerged into the Indian Ocean to the north of Western Australia's Kimberley region.

However, its organization improved significantly on 9 February, as it moved west-southwest away from the north Kimberley coast. An LNG tanker reported 40-knot winds near the center during the late afternoon of 10 February, and the storm was named Victor that night. It continued to move westward and remained weak during 11 February, but intensified during 12 February. An eye became visible during the morning of 13 February, as Victor reached peak intensity. Victor continued west-southwestward but then progressively weakened. By the morning of 15 February, the cyclone was sheared, with a fully exposed low-level center apparent on satellite imagery. Victor was a small cyclone for its whole lifetime and was surrounded by very high environmental pressures.

As Victor accelerated towards a west-southwest direction on the edge of a subtropical high, it crossed the 90th meridian east early on 16 February, subsequently being briefly renamed by Mauritius as Tropical Cyclone Cindy. Later that day, the Regional Specialised Meteorological Centre in Réunion (RSMC La Reunion) downgraded Cindy to a tropical disturbance. Cindy continued to lose its convection and vorticity until 19 February, when RSMC La Reunion reported that the cyclone dissipated, after having recurved to the south towards a polar trough.

The time period from the initial formation of the low in the Coral Sea, until it could no longer be identified as a low in the south-central Indian Ocean was 51 days.

Impact
Cyclone Katrina impacted parts of Queensland, Vanuatu, and the Solomon Islands, where it caused two deaths and $8.66 million (1998 USD) in damages. Fears were also raised that Katrina could threaten Fiji, as it interacted with Cyclone Susan, which in turn interacted with Cyclone Ron. Due to the impact of this storm, the name Katrina was retired from the lists of tropical cyclone names for the Australian region.

Katrina passed near the Solomon Islands on two separate occasions while it was active, with the cyclone first affecting the archipelago between 6–8 January, before grazing the archipelago during 11 January. As the system affected the archipelago, Katrina brought heavy rainfall, high seas and waves of about 10 m to parts of Guadalcanal, Makira-Ulawa, Malaita, Rennell and Bellona provinces. As a result of the high waves, twenty families had to abandon the village of Kopiu on the island of Guadalcanal and move to a Seventh Day Adventist school. Within the Solomon Islands, 450 homes were destroyed on the islands of Rennell and Bellona, while on southern Guadalcanal, 200 homes were destroyed, as the system brushed the islands.

The Solomon Islands National Disaster Council met on 8 January, in order to determine if any assistance was needed and if a further assessment was necessary to determine the full extent of damage. During the next day aerial and ground surveys of Rennell and Bellona and the southern parts of Makira and Guadalcanal island took place. As the cyclone affected the island nation, islanders evacuated their homes and took shelter in caves. The Red Cross and other non-government organizations provided aid within the islands. The Solomon Islands National Disaster Council also appealed, for public help and donations to help provide emergency shelter and supplies.

Vanuatu
During 8–9 January, while the system was located within the South Pacific basin, Katrina posed a threat to Vanuatu which had just been affected by Cyclone Susan a couple of days earlier. After Susan had moved away, most shops and government buildings on the island of Efate, had kept their shutters up in preparation for the system affecting the archipelago. In Vanuatu, a man drowned after being swept away by large swells and rough seas while fishing.

Australia
After battering some of these islands, the erratically tracking storm reversed direction and threatened another disaster-struck region, Queensland, Australia. By 16 January, officials warned that further rains from the storm could renew floods to regions still recovering from destructive ones earlier in the month. Residents were advised to trim branches off trees, secure outdoor objects, clean their gutters and stock up on emergency supplies. According to press reports, the threat of a landfalling cyclone was, "the worst news for Townsville." Cyclone watches were declared for parts of the Queensland coastline between Cape Melville and Bowen. Cleanup efforts were rushed as debris had to be cleared from flood-stricken areas before the storm struck. On 18 January, the 1,000 relief workers brought into the region after the floods were placed on standby to protect their well-being as the storm moved through. After Katrina stalled and turned away from Queensland on 19 January, the cyclone watch area was revised to encompass areas between Cardwell and Mackay. A strong wind warning was also put in effect from Cairns to Bowen. The following day, these advisories were discontinued as the storm no longer posed a threat to land.

Off the coast of Queensland, Willis Island was impacted by Katrina twice: once on 3 January and again between 16 and 18 January. Both instances brought heavy rains, amounting to storm total of 443.2 mm, more than twice the monthly average. While crossing the Cape York Peninsula, the remnants of Katrina brought moderate rains to the region, exceeding 60 mm in some areas.