Tropical storm Nepartak is likely to make landfall on the Pacific coast of northeastern Japan on Wednesday.
The Meteorological Agency says Nepartak was spotted 140 kilometers east of Choshi City in Chiba Prefecture at 3 p.m. on Tuesday, heading north-northwest.
It has an atmospheric pressure of 990 hectopascals at its center, packing winds of up to 72 kilometers per hour and maximum gusts of 108 kilometers per hour.
Winds of more than 54 kilometers per hour are blowing within 500 kilometers north and 390 kilometers south of the center.
Gusts of about 85 kilometers per hour were observed in Choshi City and rainfall of 25.5 millimeters in one hour was recorded in Namie Town in Fukushima Prefecture, northeastern Japan, on Tuesday afternoon.
Nepartak is likely to cause downpours accompanied by thunder in the Tohoku and Kanto-koshin regions.
For the 24 hours through late Wednesday afternoon, weather officials forecast up to 180 millimeters of rain along the Pacific coast of the Tohoku region, 100 millimeters along the Japan Sea coast of the Tohoku region, and 80 millimeters in the Kanto-koshin region.
Winds of up to 72 kilometers per hour and maximum gusts of 108 kilometers per hour are forecast for the Kanto region on Tuesday and on the Pacific coast of the Tohoku region through Wednesday.
Officials are warning of mudslides, floods in low-lying areas, swollen rivers, gusts, high waves and lightning.