Tag Archives: Southeast Asia

Tropical Storm Vamco Forms East of Vietnam

A large area of low pressure east of Vietnam developed enough organization on Sunday to be classified as Tropical Storm Vamco.  At 11:00 p.m. EDT on Sunday the center of Tropical Storm Vamco was located at latitude 14.8°N and longitude 110.0°E which put it about 160 miles (260 km) east-southeast of Da Nang, Vietnam.  Vamco was moving toward the west at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 1000 mb.

Although there is a large area of low pressure, the circulation around Tropical Storm Vamco is not well organized.  Most of the thunderstorms are located in a large rainband about 100 miles (160 km) from the center of circulation that wraps around the northern and western parts of the storm.  There are not many thunderstorms located near the center of the circulation.  Vamco is located over water where the Sea Surface Temperature is near 30°C.  However, an upper level ridge is generating northeasterly winds over the top of the storm and the vertical wind shear is inhibiting development.  Some intensification is possible in the short term, but the lack of a well formed inner core and proximity to land will limit strengthening.

A subtropical ridge north of Vamco is steering the tropical storm toward the west and that steering pattern is expected to continue.  On its anticipated track the center of Vamco will reach the central coast of Vietnam in about 18 hours.  The primary impacts will be locally heavy rainfall and the potential for flooding.

Tropical Storm Sinlaku Intensifying As It Approaches Vietnam

Tropical Storm Sinlaku is intensifying as it approaches the coast of Vietnam.  At 7:00 p.m. EST on Friday the center of Tropical Storm Sinlaku was located at latitude 12.8°N and longitude 111.7°E which put it about 200 miles east-southeast of Quy Nonh and about 310 miles southeast of Da Nang, Vietnam.  Sinlaku was moving toward the west at 12 m.p.h.  The maximum sustained wind speed was 65 m.p.h. and there were gusts to 80 m.p.h.

As the forward motion of Sinlaku slowed, the wind shear decreased.  Warm Sea Surface Temperatures (SSTs) and well developed upper level outflow created an environment favorable for intensification and the inner core of the tropical storm became better organized.  A ring of convection is forming around the center of the circulation and there are some satellite indications that an eye may be forming.  Sinlaku will remain over warm SSTs as it moves toward Vietnam and further intensification is likely.  It is possible that Sinlaku could reach typhoon intensity before it makes landfall.

Sinlaku is being steered toward the west-northwest by a subtropical ridge to its north.  That steering pattern should remain in place and Sinlaku could make landfall in 12-18 hours.  It will bring strong winds to the coast of central Vietnam and it could produce locally heavy rainfall over parts of Southeast Asia as it moves inland.

 

Tropical Storm Sinlaku Develops Over South China Sea

Spiral banding and other organizational features have increased around Tropical Depression 21W and it has intensified into Tropical Storm Sinlaku.  At 7:00 p.m. EST on Thursday the center of Tropical Storm Sinlaku was located at latitude 10.9°N and longitude 117.3°E which put it about 360 miles southwest of Manila, Philippines and about 650 miles east-southeast of Quy Nohn, Vietnam.  Sinlaku was moving toward the west-northwest at 23 m.p.h.  The maximum sustained wind speed was 40 m.p.h. and there were gusts to 50 m.p.h.

Sinlaku is being steered to the west-northwest by a subtropical ridge located to its north and that steering pattern is expected to continue for the next two or three days.  Sinlaku could be near the coast of Vietnam in about 42 hours.  The spirals bands of thunderstorms are increasing in organization and the upper level outflow is increasing.  Sinlaku will remain over warm Sea Surface Temperatures as it moves toward Vietnam.  The environmental factors suggest further intensification is likely, although the rapid forward motion of Sinlaku could limit the rate of intensification.  If Sinlaku were to move more slowly, then a faster rate of intensification night be possible.

Sinlaku is likely to bring some gusty winds to the coast of central Vietnam and it could produce locally heavy rainfall over parts of Southeast Asia as it moves inland in two or three days.