Former Tropical Storm Rai intensified to a typhoon east of the Philippines on Tuesday night. At 10:00 p.m. EST on Tuesday the center of Typhoon Rai was located at latitude 9.0°N and longitude 131.7°E which put it about 180 miles (290 km) northwest of Koror, Palau. Rai was moving toward the west at 12 m.p.h. (19 km/h). The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h). The minimum surface pressure was 981 mb.

Former Tropical Storm Rai intensified steadily on Tuesday over the Western North Pacific Ocean and it reached typhoon intensity on Tuesday night. A small circular eye formed at the center of Rai. The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Typhoon Rai. Storms near the core generated upper level divergence that pumped mass away to the west and north of the typhoon. Winds to typhoon force extended out 45 miles (75 km) from the center of Rai’s circulation. Winds to tropical storm force extended out 180 miles (290 km) from the center.

Typhoon Rai will move through an environment favorable for intensification during the next 24 hours. Rai will move over water where the Sea Surface Temperatures are near 30˚C. It will move under the southern side of an upper level ridge over the Western North Pacific Ocean. The ridge will produce easterly winds that will blow toward the top of Typhoon Rai’s circulation. Those winds will cause some vertical wind shear but the wind shear will be too small to prevent intensification. Typhoon Rai will continue to strengthen. Rai could intensify more rapidly now that an inner core with an eye and an eyewall has formed.

Typhoon Rai will move south of a surface high pressure system over the Western North Pacific Ocean. The high pressure system will steer Rai toward the west-northwest during the next several days. On its anticipated track the center of Typhoon Rai could approach northern Mindanao in 24 hours. Rai will be a typhoon when it reaches the Philippines. Typhoon Rai will bring strong winds and locally heavy rain to northern Mindanao, Siargao Island, Dinegat Island, Samar, Leyte, Cebu, Negros, Bohol and Panay Island. Rai will cause a significant storm surge along coasts where the wind blows the water toward the shore.