Typhoon Rai rapidly intensified to the equivalent of a major hurricane on Wednesday. At 4:00 p.m. EST on Wednesday the center of Typhoon Rai was located at latitude 9.5°N and longitude 128.3°E which put it about 190 miles (305 km) east of Dinagat, Philippines. Rai was moving toward the west at 13 m.p.h. (20 km/h). The maximum sustained wind speed was 130 m.p.h. (210 km/h) and there were wind gusts to 160 m.p.h. (260 km/h). The minimum surface pressure was 942 mb.

Typhoon Rai intensified very rapidly during Wednesday afternoon and it reached the equivalent of a major hurricane. . A small circular eye with a diameter of 8 miles (13 km) was at the center of Rai’s circulation. 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 of Rai generated strong upper level divergence that pumped large quantities of mass away to the west and north of the typhoon. The removal of mass allowed the surface pressure to decrease rapidly.

The circulation around Typhoon Rai increased in size as it rapidly intensified. Winds to typhoon force extended out 45 miles (75 km) from the center of Rai. Winds to tropical storm force extended out 185 miles (295 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Rai was 25.1. The Hurricane Size Index (HSI) was 17.1 and the Hurricane Wind Intensity Size Index (HWISI) was 42.2. Typhoon Rai was capable of doing regional severe damage.

Typhoon Rai will move through an environment favorable for intensification during the next 12 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 during the next 12 hours. Rai could continue to rapidly intensify during the next few hours.

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 48 hours. On its anticipated track the center of Typhoon Rai could approach northern Mindanao in 12 hours. Rai will be the equivalent of a major hurricane when it reaches the Philippines. Typhoon Rai will bring very strong winds and locally heavy rain to northern Mindanao, Siargao Island, Dinagat Island, Samar, Leyte, Cebu, Negros, Bohol and Panay Island. Heavy rain could cause flash floods in some locations. Rai will cause a significant storm surge along coasts where the wind blows the water toward the shore.