Typhoon Vamei

Typhoon Vamei (formerly had the alternate name Tropical Storm 05B) as the 32nd tropical depression (32W), the 26th named storm, and the 20th typhoon of the 2001 Pacific typhoon season. When it developed at 1.5º North, it earned the record for the storm that developed closest to the equator, breaking the record of Typhoon Sarah in 1956. In addition, Vamei was the only tropical cyclone in history to strike near the Singapore area when it hit the area in late December. Vamei crossed Indonesia and reformed in the North Indian Ocean, lasting until early the next year. The typhoon is named after a songbird with white feathers, popular as a food in Macau.http://australiasevereweather.com/cyclones/2002/summ0112.txt

Storm history

An area of convection 230 miles (370 km) east of Singapore developed from a monsoon trough disturbance under upper level divergence near the equator on December 25. It tracked westward, quickly organizing into Tropical Depression 32W on December 26 at only 1.4º north. An extremely small system, it continued to organize, and reached tropical storm strength that night only 104 miles (170 km) from the equator. Vamei's windfield was nearly cyclostrophic in nature, meaning it didn't rely on the coriolis effect to develop. Instead, it resembled a Meso-convective scale system.

With well-defined outflow on both sides of the equator and a developing eye, Vamei reached typhoon strength early on December 27, only 12 hours into its existence. Upper-level steering flow forced the typhoon westward, where the compact system reached a ship-reported peak of 87 mph sustained winds and gusts reaching 120 mphhttp://www.srh.noaa.gov/srh/jetstream/tropics/tc.htm, just hours after becoming a typhoon. At this time, the storm was only 170 miles (280 km) across, with strong winds confined to a 40 miles (65 km) radius.

Later on December 27, Vamei made landfall on the southeastern part of the Malay Peninsula, about 35 miles (60 km) northeast of Singapore. It weakened over the peninsula, and emerged into the Straits of Malacca as a weakening tropical storm. Upper level diffluence caused Vamei to retain its convection, but the mountainous terrain caused it to continue to weaken. On December 28 it made landfall in Sumatra, and further degraded to a tropical depression. Operationally, Vamei was declared dissipated over Sumatra on December 28.

Upon reaching the Indian Ocean on December 29 the remnants of Vamei re-organized, and on December 30, it became Tropical Cyclone 5B. Operationally, the remnants were declared a new system, but because postseason analysis indicated Vamei's circulation survived over Sumatra, it was re-classified as a continuation of the system. Late on December 30, Vamei became a tropical storm again, but strong mid- to upper level southwesterly winds greatly weakened the storm. Vamei lasted until the new year, but succumbed to the shear and dissipated on January 1.

Impact

Because Vamei was a very small typhoon, its effects were relatively minor, with no reported casualties. The majority of what little damage occurred involved ships that were caught off guard by the unexpected power of the storm.http://www.munichre.com Upon moving through Singapore and southern Malaysia, it brought heavy rain and flooding. Uprooted trees were seen in Vamei's path, but little other damage occurred. In addition, air traffic was disrupted at the airport in Singapore.http://www.usatoday.com/weather/resources/askjack/archives-hurricane-science.htm Traffic jams occurred from the slick roads, but the storm was downplayed as a "low pressure system".http://www.weather.org.hk/discus4/messages/41/351.html?1112802631 Overall, effects were minimal and typical of a weak typhoon.

Retirement

Because of Vamei's unique track and formation, the name was retired and replaced with Peipah.

Unusual formation

Vamei formed and reached tropical storm strength at 1.4º North, only 97 nautical miles (160 km) from the equator. The previous closest storm was Typhoon Sarah of the 1956 Pacific typhoon season, which reached tropical storm strength at 2.2º North. Cyclone Agni in the 2004 North Indian cyclone season broke Vamei's record for the closest tropical cyclone to the equator, at 0.7º North or only 48 miles (78 km) from the equator. However, Vamei formed further south, and remains the closest tropical cyclone to form to the equator. Vamei also was a relatively rare typhoon to cross from the Western Pacific into the Bay of Bengal.

External links

References

Typhon Vamei