Tropical Storm Kai-tak dropped heavy rain on places in the Philippines during the past several days. At 4:00 p.m. EST on Friday the center of Tropical Storm Kai-tak was located at latitude 12.1°N and longitude 126.8°E which put it about 150 miles (240 km) east-northeast of Tacloban, Philippines. Kai-tak was moving toward the northwest at 10 m.p.h. (16 km/h). The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h). The minimum surface pressure was 996 mb.
The distribution of thunderstorms around Tropical Storm Kai-Tak remains asymmetrical. Kai-tak is south of an upper level ridge which is producing easterly winds which are blowing toward the top of the tropical storm. Those winds are causing moderate vertical wind shear and most of the thunderstorms are developing in the western half of the circulation. The magnitude of the vertical wind shear fluctuates as the speed of the upper level winds increases or decreases. Changes in the magnitude of the wind shear contributes to fluctuations in the intensity of the thunderstorms. When the shear is stronger, most of the storms develop in the outer portion of the circulation of Kai-tak. When the upper level winds slow, thunderstorms are able to develop closer to the western core of the tropical storm. Daytime warming of the surface of some of the islands in the Philippines may increase the local instability, which also contributes to the formation of storms over those islands.
Tropical Storm Kai-tak moved very little during the past two days. As a result, heavy rain fell repeatedly over portions of Samar, Leyte, Bohol, Cebu, Negros, Panay, Masbate and southeastern Luzon. The heavy rain is creating the potential for floods and mudslides in those areas.
Tropical Storm Kaitak will move through an environment that is only marginally favorable for development. Kai-tak will move over water where the Sea Surface Temperature is near 29°C. However, the upper level ridge will continue to cause moderate vertical wind shear. Tropical Storm Kai-tak could intensify a little during the next 24 hours, but the wind shear will limit the potential for strengthening. Tropical Storm Kai-tak is likely to weaken when the center of circulation passes over islands in the Philippines.
The subtropical ridge north of Kai-tak is steering the tropical storm toward the northwest. The ridge is forecast to strengthen during the weekend and it is likely to steer Tropical Storm Kai-tak more toward the west during the next 24 to 36 hours. On its anticipated track the center of Kai-tak could reach Samar in the next 12 to 18 hours. The center could then move near Masbate and Panay.
Tropical Storm Kai-tak will continue to drop locally heavy rain on places in Samar, Leyte, Bohol, Cebu, Panay, Negros, Masbate and southern Luzon for several more days. The heaviest rain will fall in locations where the wind pushes air up the slopes of mountains. The potential for floods and mudslides will increase as more rain falls.