Cyclone Wasa–Arthur

Meteorological history

On December 3, the Fiji Meteorological Service started to monitor a shallow tropical depression, that had developed within a monsoon trough about 1,250 km (775 mi) to the north of Rarotonga, in the Southern Cook Islands. Over the next two days, the system gradually developed further as it moved towards the southwest, before during December 5, the Naval Western Oceanography Center (NWOC) started to monitor the depression and designated it as Tropical Cyclone 07P after it had become equivalent to a tropical storm. Later that day, TCWC Nadi reported that the system had developed into a category one tropical cyclone on the Australian tropical cyclone intensity scale and named it Wasa, while it was located about 250 km (160 mi) to the south-west of the Cook Islands Penhryn. During December 6, Wasa developed hurricane force winds in an area of low vertical wind shear as it performed a small clockwise loop before it started to move towards the southeast during December 8, as an equatorial westerly wind burst affected the system. Early on December 8, the NWOC reported that Wasa had peaked in intensity with 1-minute sustained wind speeds of 195 km/h (120 mph), which made it equivalent to a category 3 hurricane on the Saffir-Simpson hurricane wind scale. TCWC Nadi subsequently reported during the next day, that Wasa had become a Category 4 Severe tropical cyclone, as it reached its peak intensity with 10-minute sustained winds of 165 km/h (105 mph).

Over the next few days the system started to weaken as it passed through the French Polynesian Society Islands, and became the first major tropical cyclone to affect French Polynesia since 1983. During December 12, Wasa passed through the French Polynesian Austral Islands and passed directly over Tubuai. Later that day, TCWC Nadi reported that the system had weakened into a tropical depression, before the NWOC issued their final advisory on Wasa during December 13. However, gale force winds remained associated with the depression, in particular within the systems southeastern quadrant, the system subsequently turned and started to move towards the east-northeast and entered into warmer waters near the Tuamotus. TCWC Nadi subsequently reported during December 14, that the system had regenerated into a category one tropical cyclone and renamed it: Arthur, for various reasons including operational purposes and to avoid confusion among recipients of their warnings. During that day the system gradually intensified further, as it passed about 130 km (80 mi) to the north-northwest of the atoll: Mururoa, with the automatic weather station there reporting sustained wind speeds of 70 km/h (45 mph). At 12:00 UTC TCWC Nadi reported that Wasa–Arthur had re-peaked with 10-minute sustained wind speeds of 95 km/h (60 mph), which made it a category 2 tropical cyclone on the Australian scale. During the next day the system maintained its peak intensity and moved through the uninhabited Acteon Group of islands and several other atolls, before as Wasa-Arthur turned eastwards, the NWOC decided to classify the storm as Tropical Cyclone 08P, with peak 1-minute sustained wind speeds of 85 km/h (55 mph). During December 16, the system started to gradually weaken as it turned more towards the east, before it degenerated into a shallow depression late the next day. The remnant depression was last noted dissipating during December 18, to the north of the Pitcairn islands.

Preparations and impact

During December 9, ahead of Cyclone Wasa affecting French Polynesia, the High Commissioner Jean Montpezat, declared a state of maximum alert which closed schools and banned navigation. On December 12, tourists on the island of Bora Bora were evacuated to a local church, after the system had swept high seas into tourist bungalows. Overall Cyclone Wasa–Arthur caused an estimated 7007600000000000000♠US$60 million in damage within the six Leeward Islands, the two Windward Islands of Tahiti and Moorea and several of the Austral Islands with the majority of the damage done between December 9 – 12. The system destroyed 367 homes, damaged 855 other homes, destroyed or damaged a variety of crops and damaged several public buildings, hotels, roads and power installations, with the worst affected islands were Bora Bora and Tubuai. On Rurutu island, Moerai harbour was destroyed by a cyclonic swell generated by the system, while the local school and police station were destroyed by high waves. A women and her child were killed while asleep, after torrential rainfall from Wasa caused a mudslide on the island of Moorea the day after the system had made its closest approach to the island.

During the aftermath of the cyclone, a French Military cargo plane and several helicopters carried out initial relief efforts to several of the islands affected by Wasa, before the French Polynesian Government and private cargo ships continued the effort, by carrying emergency relief supplies and reconstruction materials. The French Government's Minister for Overseas France: Louis Le Pensec arrived in Tahiti on December 15, to inspect the damage and explore ways of rebuilding the island nation, after similar tours were conducted by the President of French Polynesia, Gaston Flosse and several of his cabinet ministers. During the emergency period, the French Government incurred costs of about 7007680000000000000♠FF68 million including 7007530000000000000♠FF53 million for the efforts of the French Military. The French Polynesian Government subsequently borrowed 7007550000000000000♠FF55 million from the Central Fund for Economic Cooperation and built up a fund from local banks of about 7009150000000000000♠FF1.5 billion, to help with the reconstruction of infrastructure and territorial buildings. The name Wasa was later retired, from the list of tropical cyclone names by the World Meteorological Organization.