Tropical Storm Vamei
Meteorological history | |
---|---|
Formed | 26 December 2001 |
Dissipated | 28 December 2001 (1 January 2002 per JTWC) |
Tropical storm | |
10-minute sustained (JMA) | |
Highest winds | 85 km/h (50 mph) |
Lowest pressure | 1006 hPa (mbar); 29.71 inHg |
Category 1-equivalent typhoon | |
1-minute sustained (SSHWS/JTWC) | |
Highest winds | 120 km/h (75 mph) |
Lowest pressure | 976 hPa (mbar); 28.82 inHg |
Overall effects | |
Fatalities | 5 direct |
Damage | $3.58 million (2001 USD) |
Areas affected | Singapore, Malaysia, Indonesia |
IBTrACS | |
Part of the 2001 Pacific typhoon season |
Tropical Storm Vamei (also known as Typhoon Vamei) was a
Though Vamei was officially designated as a tropical storm, its intensity is disputed; some agencies classify it as a typhoon, based on sustained winds of 120 km/h (75 mph) and the appearance of an eye. The storm brought flooding and landslides to eastern Peninsular Malaysia, causing $3.58 million in damage (2001 USD, $6.16 million 2024 USD) and five deaths.
Meteorological history
On 19 December, a small low-level circulation was located along the northwest coastline of Borneo; at the same time a plume of cold air progressed southward through the South China Sea on the southeastern periphery of a ridge over the Far East. The vortex drifted southwestward, reaching open water by 21 December. The northerly air surge was deflected after interacting with the circulation, and at the same time a portion of the air surge crossed the equator. The southerly flow turned eastward, then northward, and in combination with the northerly flow it wrapped into the vortex, resulting in rapid development of the low-level circulation, just a short distance north of the equator.[1] By 25 December, an area of scattered convection persisted about 370 km (230 mi) east of Singapore within an area of low wind shear, in association with the low-level circulation. Continuing slowly westward, the convection deepened and organized further,[2] and at 12:00 UTC on 26 December the disturbance developed into a tropical depression about 230 km (140 mi) east of Singapore, or 156 km (97 mi) north of the equator.[3] This was the first recorded occurrence of a tropical cyclone near the equator.[1]
The depression strengthened further and officially attained tropical storm status at 00:00 UTC on 27 December, based on the analysis by the Japan Meteorological Agency (JMA),[3] though the Joint Typhoon Warning Center (JTWC) unofficially classified it as a tropical storm six hours prior. Shortly thereafter, an eye with a 39 km (24 mi) diameter became apparent on satellite imagery, along with rainbands extending southward to the opposite side of the equator. At 06:00 UTC, the JMA first classified the system as Tropical Storm Vamei, about 65 km (40 mi) northeast of Singapore,[2] and the agency estimated the storm attained peak winds of 85 km/h (55 mph) at the same time.[3] However, the JTWC upgraded Vamei to typhoon status with peak winds of 120 km/h (75 mph),[nb 1] based on a United States Navy ship report from within the eye; a second ship reported wind gusts of 195 km/h (120 mph) in the southern portion of the eyewall. The storm was small and compact, with gales extending about 45 km (28 mi) from its center. At about 0830 UTC on 27 December, Vamei made landfall approximately 60 km (37 mi) northeast of Singapore,[2] in the southeastern portion of the Malaysian state of Johor.[4] Initially, the Malaysian Meteorological Department (MetMalaysia) classified the cyclone as a tropical storm,[5] though it was later re-assessed as a typhoon at landfall.[6]
Vamei weakened quickly as it crossed the extreme southern portion of the Malay Peninsula, and late on 27 December, the JMA downgraded it to tropical depression status before the cyclone emerged into the
Unusual formation
Vamei formed and reached tropical storm strength at
Vamei developed in a vortex that appears every winter along the northwest coast of Borneo and is maintained by the interaction between monsoonal winds and the local topography. Often, the vortex remains near the coastline, and in an analysis of 51 winters, only six reported the vortex as being over the equatorial waters for four days or more. As the area in the South China Sea between Borneo and Singapore is only 665 km (413 mi) wide, a vortex needs to move slowly to develop. A persistent northerly wind surge for more than five days, which is needed to enhance the vortex, is present, on average, nine days each winter. The probability for a pre-existing tropical disturbance to develop into a tropical cyclone is between 10 and 30 percent. Thus, the conditions which resulted in the formation of Vamei are believed to occur once every 100–400 years.[1]
Preparations and impact
Four days prior to Vamei moving ashore, the Malaysian Meteorological Department (MetMalaysia) issued storm advisories for potentially affected areas. Subsequently, the agency issued warnings for heavy rainfall, high winds, and rough seas.[4] However, few citizens knew of the passage of the rare storm.[7]
Offshore of Malaysia, two
Retirement
In 2004, the name "Vamei" was retired and replaced with "Peipah", becoming the first retired name since the Japan Meteorological Agency began naming Pacific typhoons in 2000.[14][15]
See also
Notes
- ^ The JTWC operationally assessed the storm's peak winds to have been 140 km/h (85 mph).
References
- ^ a b c d e C.P. Chang; Ching-Hwang Liu; Hung-Chi Kuo (2003). "Typhoon Vamei: An Equatorial Tropical Cyclone Formation". Naval Postgraduate School Department of Meteorology. Archived from the original on 23 July 2012. Retrieved 14 April 2010.
- ^ a b c d e f g Gary Padgett (2002). "December 2001 Worldwide Tropical Weather Summary". Retrieved 14 April 2010.
- ^ a b c d e f RSMC Tokyo — Typhoon Center. "Typhoon Vamei Best Track for the 2001 Pacific typhoon season" (PDF) (in Japanese). Japan Meteorological Agency. Retrieved 6 December 2012.
- ^ a b c Malaysian Meteorological Department. "Tropical Storm Vamei causes widespread floods in Johor". Archived from the original on 25 May 2008. Retrieved 14 April 2010.
- ^ Zahar (20 December 2006). "Change Welcomed". New Straits Times (Malaysia). Archived from the original on 20 March 2015. Retrieved 9 March 2008.
- ^ Leong Chow Peng (14 November 2006). "Typhoon Vamei a unique experience". New Straits Times (Malaysia). Archived from the original on 20 March 2015. Retrieved 9 March 2008.
- ^ Zahar A. (1 May 2006). "Get your facts right first". New Straits Times (Malaysia). Archived from the original on 21 March 2015. Retrieved 9 March 2008.
- ^ Cheryl Dybas (12 May 2003). "Hurricanes at the Equator: "Impossible Perfect Storm" Observed". National Science Foundation. Archived from the original (press release) on 29 September 2007. Retrieved 14 April 2010.
- ^ Richard H. Johnson & Chih-Pei Chang (2007). "Winter Vortex: A Quarter-Century and Beyond" (PDF). American Meteorological Society. Retrieved 14 April 2010.
- ^ a b Mahathir Told (8 January 2002). "Recent Floods Claimed Five Lives and Caused Substantial Damage" (PDF). Bernama: The Malaysian National News Agency. Archived from the original (PDF) on 21 December 2014. Retrieved 7 March 2008.
- ^ T.Y. Koh & H. Lim (2005). "Verification of a Mesoscale Simulation of Tropical Cyclone Vamei" (PDF). European Geosciences Union. Retrieved 14 April 2010.
- ^ Jack Williams (1 November 2004). "Why don't certain areas in Asia, like Singapore, have typhoons, tornadoes or other disastrous weather?". USAToday.com. Retrieved 14 April 2010.
- ^ Tieh-Yong Koh (2005). "What Makes A Typhoon Spin?" (DOC). School of Physical & Mathematical Sciences, Nanyang Technological University. Retrieved 14 April 2010.
- ^ Tropical Cyclone Programme (2008). "Typhoon Committee Operational Manual — Meteorological Component" (PDF). World Meteorological Organization. Archived from the original (PDF) on 17 July 2012. Retrieved 14 April 2010.
- ^ Hong Kong Observatory (2007). "Tropical Cyclones in 2006". Archived from the original on 7 February 2012. Retrieved 14 April 2010.
External links
- RSMC Tokyo – Typhoon Center
- Best Track Data of Tropical Storm Vamei (0126) (in Japanese)
- Best Track Data (Graphics) of Tropical Storm Vamei (0126)
- Best Track Data (Text)
- JTWC Best Track Data of Typhoon 32W (Vamei)