A center of circulation formed within a cluster of thunderstorms east of Mindanao on Saturday and the system was designated Tropical Depression 01W. At 10:00 p.m. EST on Saturday the center of Tropical Depression 01W was located at latitude 9.2°N and longitude 126.5°E which put it about 200 miles (320 km) east-southeast of Cebu, Philippines. The depression was moving toward the northwest at 10 m.p.h. The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 km/h). The minimum surface pressure was 1000 mb.
Although there is a distinct center of circulation in Tropical Depression 01W, the distribution of thunderstorms is asymmetrical. Most of the stronger thunderstorms are forming in the northern half of the circulation and there are few thunderstorms in the southern half of the circulation. The thunderstorms in the northern half of the circulation are generating upper level divergence that is pumping out mass toward the northeast and northwest of the tropical depression.
Tropical Depression 01W will be moving through an oceanic and atmospheric environment that is somewhat favorable for intensification. It will move over water where the Sea Surface Temperature is near 28°C. An upper level ridge is generating southeasterly winds which are blowing across the top of the depression, but the vertical wind shear is not too strong. However, the center of Tropical Depression 01W will move over some of the islands of the southern Philippines. Increases friction and high topography will disrupt the circulation each time the center moves over land. The intermittent passages overland will cause weakening and the intensity of Tropical Depression 01W is likely to fluctuate during the next several days.
A subtropical ridge north of the depression is steering it toward the northwest. The ridge is forecast to strengthen and it is predicted to steer Tropical Depression 01W in a general westerly direction during the next several days. On its anticipated track the center of Tropical Depression 01W will pass near northern Mindanao, Siargao Island, Dinogat Island, Leyte, Bohol Island, Cebu, Negros, and Panay Island.
Heavy rain associated will be the greatest threat with Tropical Depression 01W. The heaviest rain will fall north of where the center moves. The heavy rain could cause flooding and mudslides,