Tropical Storm Usagi formed over the Western North Pacific Ocean east of the Philippines on Monday.  At 4:00 p.m. EST on Monday the center of Tropical Storm Usagi was located at latitude 13.0°N and longitude 134.2°E which put the center about 945 miles (1525 km) east of Manila, Philippines.  Usagi was moving toward the west at 17 m.p.h. (28 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 991 mb.

Another tropical storm formed east of the Philippines on Monday.  Former Tropical Depression Twentyseven-W strengthened and the Japan Meteorological Agency designated the system as Tropical Storm Usagi.  More thunderstorms formed near the center of Usagi’s circulation.  However, the distribution of thunderstorms in Tropical Storm Usagi was asymmetrical.  Many of the thunderstorms were occurring in bands in the western half of Usagi’s circulation.  Bands in the eastern half of Tropical Storm Usagi consisted primarily of showers and lower clouds.  Storms near the center of Usagi generated upper level divergence that pumped mass away to the west of the tropical storm.

The circulation around Tropical Storm Usagi was small.  Winds to tropical storm force extended out 50 miles (80 km) from the center of Usagi’s circulation.

Tropical Storm Usagi will move through an environment favorable for intensification during the next 24 hours.  Usagi 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 upper level ridge will produce easterly winds that will blow toward the top of Usagi’s circulation.  Those winds will cause some vertical wind shear.  The wind shear will inhibit intensification, but the shear will not be enough to prevent intensification.  Tropical Storm Usagi will intensify during the next 24 hours.  Usagi could strengthen to a typhoon on Tuesday.

Tropical Storm Usagi will move around the southern side of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Usagi toward the west-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Usagi will move toward the Philippines.

Elsewhere over the Western North Pacific Ocean, former Typhoon Toraji weakened as it moved away from the Philippines, Tropical Storm Yinxing approached the coast of Vietnam, Tropical Storm Watches were issued in the Marianas for Tropical Storm Man-yi.

At 4:00 p.m. EST on Monday the center of Tropical Storm Toraji was located at latitude 18.5°N and longitude 118.7°E which put the center about 420 miles (675 km) southeast of Hong Kong.  Toraji was moving toward the west-northwest at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 75 m.p.h. (120 km/h).  The minimum surface pressure was 985 mb.

At 4:00 p.m. EST on Monday the center of Tropical Storm Yinxing was located at latitude 14.6°N and longitude 109.6°E which put the center about 130 miles (210 km) southeast of Da Nang, Vietnam.  Yinxing was moving toward the south-southwest at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 999 mb.

At 4:00 p.m. EST on Monday the center of Tropical Storm Man-yi was located at latitude 14.0°N and longitude 150.5°E which put the center about 430 miles (695 km) east of Guam.  Man-yi was moving toward the west-southwest at 8 m.p.h. (13 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 992 mb.

Tropical Storm Watches were in effect for Guam, Rota, Tinian and Saipan.