December 14, 2010
NASA Satellite Sees Remnants of Tropical Depression 19W Added to Vietnam's Rainfall
Hurricane Season 2010: Tropical Depression 19W (Northwestern Pacific Ocean)
Tropical Depression 19W was alive as a depression for only two days in the waters of the Northwestern Pacific Ocean basin and as it wanes it still had some strong thunderstorms within, according to NASA's TRMM Satellite. Those thunderstorms have added to the rainfall flooding woes already being experienced in Vietnam.
Tropical Depression 19W (TD 19W) became a remnant low pressure area on Dec. 13 at 0900 UTC (4 a.m. EST) when its center was located about 225 miles east of Ho Chi Minh, Vietnam near 10.2 North and 110.4 East. At that time, its maximum sustained winds were only near 23 mph (20 knots) and it had higher gusts over 30 mph. It was slowly moving west at 5 mph through the South China Sea (part of the Northwestern Pacific Ocean basin). TD 19W was kicking up wave heights to nine feet in the South China Sea.
When NASA's Aqua satellite passed over TD 19W's remnants on Dec. 13 at 16:23 UTC (11:23 a.m. EST) the western edge of the system was stretching into southeastern Vietnam.
Tropical depression 19W was the latest of four tropical cyclones to move over Vietnam this season. The Tropical Rainfall Measuring Mission (TRMM) satellite passed directly above TD 19W on December 13, 2010 at 2038 UTC (3:38 p.m. EST) and collected rainfall data. TRMM's Precipitation Radar (PR) showed that a few powerful thunderstorms embedded within TD 19W were dropping heavy rainfall off Vietnam's south-eastern coast. The heaviest rainfall was falling at a rate of about 2 inches per hour over the coastal waters of Vietnam. TRMM is a joint mission between NASA and the Japanese space agency JAXA.
Although TD 19W was very small it's rainfall added to October's extreme rainfall amounts that contributed to the worst flooding seen in the country of Vietnam for 20 years. Flooding was widespread in the central provinces of Nghe An, Quang Tri, Quang Binh, Thua Thien Hue, and Ha Tinh. Deadly tropical storms Mindulle and Conson hit Vietnam in July and August. Tropical depression 18W in November also added to Vietnam's extremely high 2010 rainfall totals.
According to the Joint Typhoon Warning Center, the organization that forecasts tropical cyclones in that area of the world, TD 19W's remnant s have already moved ashore and are now affecting southern and central Cambodia.
Hal Pierce/Rob Gutro
SSAI/NASA Goddard Space Flight Center
, Greenbelt, MD
December 13, 2010
NASA's Aqua Satellite Sees Tropical Depression 19W in Two Seas
The South China Sea and the Sulu Sea are side-by-side in the Western Pacific Ocean basin, and where they are separated by the Philippine island of Palawan, that's where the newest tropical depression was sitting yesterday.
On Dec. 12 at 541 UTC (12:31 a.m. EST), the Atmospheric Infrared Sounder (AIRS) instrument that flies aboard NASA's Aqua satellite captured an infrared image of Tropical Depression 19W's clouds, which were centered over Palawan. Palawan is an island province of the Philippines located in the Mimaropa region that stretches from southwest to northeast. Palawan lies between the South China Sea to its west and the Sulu Sea to its east, and Tropical Depression 19W's center was directly over Palawan at the time, and over both seas. AIRS data showed the thunderstorms in the center of Tropical Depression 19W's were as cold as or colder than -63 Fahrenheit, indicating strong storms.
Tropical Depression 19W (TD 19W) formed on Sunday, December 12 in the morning hours (UTC) and is headed west-northwest toward Vietnam. At time it formed, it was about 325 miles east of Ho Chi Minh, Vietnam. Today, December 13, at 0900 UTC (4 a.m. EST), TD 19W's maximum sustained winds had weakened to 20 knots (23 mph). It was about 225 nautical miles east of Ho Chi Minh City, Vietnam, near 10.3 North latitude and 110.1 East longitude. It was moving west-northwest at 5 mph.
Animated multispectral satellite imagery shows that TD 19W is now being buffeted by strong vertical wind shear (winds that can weaken a tropical cyclone and tear it apart), which is why it weakened since yesterday. Its low level-circulation center is now fully exposed to outside winds, and that's an indication that the system can weaken further. Satellite imagery from this morning indicates that convection (rapidly rising air that form the thunderstorms that power the tropical cyclone) are waning.
The Joint Typhoon Warning Center (JTWC) is the organization forecasting for TD 19W. JTWC is a joint United States Navy – United States Air Force task force located at the Naval Maritime Forecast Center in Pearl Harbor, Hawaii.
JTWC expects TD 19W will continue to track west-northwestward and into an area of even strong vertical wind shear. As a result of those battering winds, TD 19W is expected to keep weakening until it makes landfall in southern Vietnam on December 14 at 0600 UTC (1 a.m. EST) far north of Ho Chi Minh.
NASA Goddard Space Flight Center
, Greenbelt, MD