Tropical Storm Lan moved over the Sea of Japan on Tuesday. At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Lan was located at latitude 38.7°N and longitude 135.8°E which put it about 220 miles (355 km) west-southwest of Akita, Japan. Lan was moving toward the north-northeast at 14 m.p.h. (22 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 989 mb.

Tropical Storm Lan moved over the Sea of Japan on Tuesday after it crossed Honshu near Osaka. Lan weakened to a tropical storm as it crossed over Honshu. The distribution of thunderstorms in Tropical Storm Lan was asymmetrical on Tuesday night. Most of the thunderstorms were occurring in bands in the northern half of Lan’s circulation. Bands in the southern half of the circulation consisted primarily of showers and lower clouds. Storms in the northern half of Lan generated upper level divergence that pumped mass away to the north of the tropical storm. Winds to tropical storm force extended out 150 miles (240 km) from the center of Tropical Storm Lan.

Tropical Storm Lan will move through an environment that will be unfavorable for intensification during the next 36 hours. Lan will move over water where the Sea Surface Temperatures are near 28°C. It will move under the eastern part of an upper level trough that is northwest of Japan. The upper level trough will produce southwesterly winds that will blow toward the top of Lan’s circulation. Those winds will cause moderate vertical wind shear. The moderate wind shear will prevent intensification of Tropical Storm Lan. Lan will begin a transition to an extratropical cyclone in a day or so when it moves over colder water.

The upper level trough that is northwest of Japan will steer Tropical Storm Lan toward the northeast during the next 36 hours. On its anticipated track, The center of Tropical Storm Lan will pass west of Hokkaido in 24 hours. Lan could approach Sakhalin Island in 36 hours.

Elsewhere over the Western North Pacific Ocean, former Tropical Storm Dora weakened to a tropical depression north-northeast of Wake Island. At 11:00 p.m. EDT on Tuesday the center of Tropical Depression Dora was located at latitude 25.0°N and longitude 168.4°E which put it about 380 miles (610 km) north-northeast of Wake Island. Dora was moving toward the north-northeast at 14 m.p.h. (22 km/h). The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 km/h). The minimum surface pressure was 1008 mb.