Tropical Storm Malakas Spins South-southwest of Guam

Tropical Storm Malakas spun south-southwest of Guam on Friday night. At 11:00 p.m. EDT on Friday the center of Tropical Storm Malakas was located at latitude 7.4°N and longitude 144.1°E which put it about 460 miles (740 km) south-southwest of Guam. Malakas was moving toward the north at 6 m.p.h (10 km/h). The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h). The minimum surface pressure was 997 mb.

An upper level ridge over the Western North Pacific strengthened on Friday and that increased the vertical wind shear affecting Tropical Storm Malakas. The increased wind shear prevented Malakas from strengthening on Friday. When the upper level ridge strengthened, the easterly winds blowing toward the top of Malakas’ circulation strengthened. Those stronger upper level winds increased the vertical wind shear and they caused the distribution of thunderstorms around Tropical Storm Malakas to become asymmetrical. The strongest thunderstorms were occurring in bands in the western half of Malakas’ circulation. Bands in the eastern half of the tropical storm consisted primarily of showers and lower clouds. Winds to tropical storm force extended out 90 miles (145 km) from the center of circulation.

Tropical Storm Malakas will move through an environment more favorable for intensification during the next 36 hours. Malakas will move over water where the Sea Surface Temperatures are near 29˚C. It will move under the southern part of an upper level ridge over the Western North Pacific Ocean. The ridge will produce easterly winds that will blow toward the top of Malakas’ circulation. Those winds will cause some vertical wind shear, but the shear is forecast to decrease during the weekend. Tropical Storm Malakas will intensify during the next 36 hours. Malakas could strengthen to a typhoon during the weekend.

Tropical Storm Malakas will move around the southwestern part of a high pressure system over the Western North Pacific Ocean during the next several days. The high pressure system will steer Malakas toward the northwest. On its anticipated track Tropical Storm Malakas could pass between Guam and Yap during the weekend.

Elsewhere over the Western North Pacific Ocean, Tropical Depression 03W developed east of the Philippines. At 11:00 p.m. EDT on Friday the center of Tropical Depression 03W was located at latitude 10.8°N and longitude 126.8°E which put it about 265 miles (425 km) southeast of Legazpi, Philippines. The tropical depression was moving toward the south-southwest at 4 m.p.h (6 km/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 1006 mb.