Tropical Storm Yun-Yeung moved toward Honshu on Wednesday. At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Yun-yeung was located at latitude 30.2°N and longitude 136.7°E which put it about 430 miles (695 km) south-southwest of Tokyo, Japan. Yun-yeung was moving toward the north-northeast at 15 m.p.h. (24 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 994 mb.

Tropical Storm Yun-yeung consisted primarily of a low level circulation on Wednesday night. The bands revolving around the center of Yun-yeung’s circulation contained primarily showers and lower clouds. A strong upper level trough northwest of Japan produced strong southwesterly winds that blew across the top of Tropical Storm Yun-Yeung. Those winds caused strong vertical wind shear and the winds blew the upper part of Yun-Yeung’s circulation to the northeast of the circulation near the surface . There was a band of thunderstorms near the northern periphery of Tropical Storm Yun-yeung. Winds to tropical storm force extended out 100 miles (160 km) in the eastern side of Yun-Yeung’s circulation. The winds in the western side of Yun-yeung were blowing at less than tropical storm force.

Tropical Storm Yun-yeung will move through an environment unfavorable for intensification of a tropical storm during the next 36 hours. Yun-yeung will move over water where the Sea Surface Temperatures are near 28°C. However, the upper level trough northwest of Japan will continue to cause strong vertical wind shear. The strong vertical wind shear will prevent intensification of Tropical Storm Yun-yeung. Yun-yeung could get a little stronger, if it makes a transition to an extratropical cyclone.

Tropical Storm Yun-yeung will move around the northwestern part of high pressure system over the Western North Pacific. The high pressure system and the upper level trough northwest of Japan will steer Yun-yeung toward the northeast during the next 36 hours. On its anticipated track, Tropical Storm Yun-yeung will approach Tokyo in 36 hours.

Tropical Storm Yun-yeung formed over the Western North Pacific Ocean south of Japan on Tuesday night. At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Yun-yeung was located at latitude 26.2°N and longitude 133.6°E which put it about 810 miles (1305 km) south-southwest of Tokyo, Japan. Yun-yeung was moving toward the north at 17 m.p.h. (28 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 998 mb.

A low pressure system over the Western North Pacific Ocean strengthened on Tuesday and the Japan Meteorological Agency designated the system as Tropical Storm Yun-yeung. More thunderstorms developed near the center of Yun-yeung’s circulation on Tuesday evening, but the distribution of thunderstorms was asymmetrical. Most of the thunderstorms were occurring in bands in the southern half of Tropical Storm Yun-yeung. Bands in the northern half of the circulation consisted primarily of showers and lower clouds. The distribution of wind speeds was also asymmetrical. Winds to tropical storm force extended out 40 miles (65 km) in the eastern side of Yun-yeung’s circulation. The winds in the eastern side of Yun-yeung were blowing at less than tropical storm force.

Tropical Storm Yun-yeung will move through an environment somewhat favorable for intensification during the next 24 hours. Yun-yeung will move over water where the Sea Surface Temperatures are near 28°C. It will move under the eastern side on an upper level ridge south of Japan. The upper level ridge will produce northeasterly winds that will blow toward the top of Yun-yeung’s circulation. Those winds will cause moderate vertical wind shear. The wind shear is already contributing to the asymmetrical distribution of thunderstorms. The vertical wind shear will inhibit intensification, but the shear will probably not be strong enough to prevent Yun-yeung from strengthening. Tropical Storm Yun-yeung is likely to intensify gradually during the next 24 hours.

Tropical Storm Yun-yeung will move around the northwestern part of high pressure system over the Western North Pacific. The high pressure system will steer Yun-yeung toward the north-northeast during the next 24 hours. On its anticipated track, Tropical Storm Yun-yeung will move closer to Honshu. Yun-yeung could be near Tokyo in 48 hours.