Tropical Storm Vongfong developed east of the Philippines on Tuesday.  At 11:00 a.m. EDT on Tuesday the center of Tropical Storm Vongfong was located at latitude 11.6°N and longitude 128.7°E which put it about 165 miles (270 km) east of Samar, Philippines.  Vongfong was moving toward the north-northwest at 7 m.p.h. (11 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 1002 mb.

Former Tropical Depression 01W strengthened on Tuesday and the Japan Meteorological Agency designated the low pressure system as Tropical Storm Vongfong.  The circulation around Vongfong was still organizing.  More thunderstorms were developing near the center of circulation.  Other thunderstorms were occurring in a primary rainband in the eastern side of Tropical Storm Vongfong.  Bands in the northern and western parts of the circulation consisted primarily of showers and lower clouds.  Storms near the center of circulation were generating upper level divergence which was pumping mass away from the tropical storm.  Winds to tropical storm force extended out 75 miles (120 km) from the center.

Tropical Storm Vongfong will move through an environment favorable for intensification during the next 36 hours.  Vongfong will move over water where the Sea Surface Temperature is near 29°C.  It will move under a small upper level ridge centered east of the Philippines.  The winds in upper ridge are weak and there will be little vertical wind shear.  Tropical Storm Vongfong will continue to intensify and it could strengthen to a typhoon within 24 to 36 hours.  A period of rapid intensification could occur after the inner part of the circulation becomes more organized.

Tropical Storm Vongfong will move around the western end of a high pressure system centered south of Japan.  The high pressure system is forecast to strengthen during the next 36 hours and it will steer Vongfong more toward the west-northwest on Wednesday.  On its anticipated track Tropical Storm Vongfong could approach northern Samar and southeastern Luzon in 36 to 48 hours.  Vongfong could be a typhoon at that time.  It could also drop locally heavy rain and cause flash floods over northeastern parts of the Philippines.