Typhoon Shanshan moved steadily closer to Honshu on Tuesday. At 11:00 p.m. EDT on Tuesday the center of Typhoon Shanshan was located at latitude 33.7°N and longitude 141.6°E which put it about 190 miles (305 km) southeast of Tokyo. Shanshan was moving toward the north-northwest at 12 m.p.h. (19 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 965 mb.
Typhoon Shanshan intensified earlier on Tuesday and it started to weaken on Tuesday night. There was a circular eye at the center of circulation. The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms. Several bands of showers and thunderstorms were revolving around the core of Typhoon Shanshan. The rainbands south and east of the center were stronger and the rainbands north and west of the center were weaker. Storms near the core of Shanshan were generating upper level divergence which was pumping mass away from 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 220 miles (350 km) from the center.
Typhoon Shanshan will move through an environment on Wednesday that should allow it to remain a typhoon until it reaches Japan. Shanshan will move over water where the Sea Surface Temperature is near 28°C. It will move through a region where the upper level winds are weaker and there will be little vertical wind shear. Typhoon Shanshan will move into a region in a day or so where stronger upper level winds will blow from the west. Vertical wind shear will increase at that time and Typhoon Shanshan will start to weaken more quickly.
Typhoon Shanshan will move around the western end of a ridge over the North Pacific Ocean and the ridge will steer the typhoon toward the north on Wednesday. When Shanshan gets close to the coast of Honshu, the westerly winds will turn the typhoon toward the east. On its anticipated track Typhoon Shanshan could make landfall on the coast of Honshu east of Tokyo in 18 to 24 hours. Shanshan will bring gusty winds and it could drop heavy rain over coastal regions of eastern Honshu.