Former Tropical Storm Yutu strengthened into a typhoon east of the Marianas on Monday evening. At 11:00 p.m. EDT on Monday the center of Typhoon Yutu was located at latitude 11.8°N and longitude 151.2°E which put it about 475 miles (770 km) east-southeast of Guam. Yutu was moving toward the west-northwest at 14 m.p.h. (22 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 975 mb.
A Typhoon Warning was in effect for Tinian and Saipan. A Tropical Storm Warning was in effect for Rota. Tropical Storm Watches were in effect for Guam, Alamagan, Pagan and Agrihan.
The circulation around Typhoon Yutu became better organized on Monday. An inner rainband wrapped around the northern and western sides of the center of circulation. A partial eyewall appeared to be forming. Several bands of showers and thunderstorms were revolving around the center of Typhoon Yutu. The strongest thunderstorms were developing in the bands in the eastern half of the circulation. There were thunderstorms in bands in the western side of Typhoon Yutu, but those bands consisted primarily of showers and lower clouds. Winds to typhoon force extended out about 60 miles (95 km) from center center of circulation. Winds to tropical storm force extended out about 160 miles (260 km) from the center.
Typhoon Yutu will move through an environment favorable for intensification during the next two or three days. Yutu will move over water where the Sea Surface Temperature is near 30°C. It will move through an environment where the upper level winds are weak and there will be little vertical wind shear. Yutu will continue to intensify and it could strengthen into the equivalent of a major hurricane in a day or two.
Typhoon Yutu will move around the southwestern portion of an ridge of high pressure over the Western North Pacific Ocean. The ridge will steer Typhoon Yutu toward the west-northwest during the next few days. On its anticipated track Typhoon Yutu will move over the Northern Marianas in about 36 to 48 hours. Yutu will be a typhoon when it reaches the Marianas. It will bring strong winds and it could be capable of causing major damage.