Former Tropical Storm Jelawat strengthened into a typhoon as it moved west-northwest of Guam on Thursday. At 11:00 p.m. EDT on Thursday the center of Typhoon Jelawat was located at latitude 15.9°N and longitude 137.7°E which put it about 520 miles (840 km) west-northwest of Guam. Jelawat was moving toward the east-northeast at 7 m.p.h. (11 km/h). The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 115 m.p.h. (185 km/h). The minimum surface pressure was 972 mb.
Typhoon Jelawat strengthened quickly on Thursday night. A small eye developed at the center of circulation. A ring of strong thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms. Several bands of showers and thunderstorms were revolving around the core of Typhoon Jelawat. Storms in the core of the circulation were generating upper level divergence which was pumping mass away to the northeast of the typhoon. Winds to typhoon force extended out about 45 miles (75 km) from the center of circulation. Winds to tropical storm force extended out about 145 miles (230 km) from the center.
Typhoon Jelawat will move through an area favorable for intensification on Friday. Jelawat will move over water where the Sea Surface Temperature is near 28°C. Typhoon Jelawat has moved around the western end of an upper level ridge which is producing southwesterly winds which are blowing toward the top of the circulation. Those winds are producing some vertical wind shear, but the wind shear is not strong enough to prevent intensification. Typhoon Jelwat is likely to intensify further on Friday.
The upper level ridge is steering Typhoon Jelawat toward the east-northeast and that general motion is expected to continue for several more days. On its anticipated track Typhoon Jelawat is expected to pass northwest of Guam. Jelawat could approach the northernmost islands in the Marianas in about two or three days.