Former Tropical Storm Sepat weakened to a tropical depression over the Western North Pacific Ocean south of Japan on Tuesday.  At 11:00 p.m. EDT on Tuesday the center of Tropical Depression Sepat was located at latitude 32.4°N and longitude 139.5°E which put the center about 230 miles (370 km) south of Tokyo, Japan.  Sepat was moving toward the north-northwest at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 1005 mb.

Former Tropical Storm Sepat weakened to a tropical depression on Tuesday as it moved over the Western North Pacific Ocean south of Japan.  Many of the thunderstorms in Sepat’s circulation dissipated.  A few thunderstorms were still occurring in the southeastern quadrant of Tropical Depression Sepat.  Most of the bands revolving around the center of Sepat’s circulation consisted primarily of showers and lower clouds.

Tropical Depression Sepat will move through an environment that will be unfavorable for intensification during the next 24 hours.  Sepat will move over water where where the Sea Surface Temperatures are near 25°C.  It will move under the northern part of an upper level ridge south of Japan.  The upper level ridge will produce west-southwesterly winds that will blow toward the top of Sepat’s circulation.  Those winds will cause strong vertical wind shear.  The strong vertical wind shear and marginal Sea Surface Temperatures will cause Tropical Depression Sepat to continue to weaken during the next 24 hours.

Tropical Depression Sepat will move around the western end of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Sepat toward the north during the next 24 hours.  On its anticipated track, Tropical Depression Sepat will approach eastern Honshu in 12 hours.  The center of Sepat’s circulation is likely to pass just to the southeast of Tokyo.

Tropical Depression Sepat is likely to bring gusty winds and rain to the part of Honshu southeast of Tokyo.