Typhoon Koppu was moving north-northeastward off the coast of Honshu on Monday evening, gathering strength and generating strong winds on islands south of Tokyo, the Japan Meteorological Agency said.
At 6 p.m., the season's 16th typhoon was about 180 km north of Chichijima Island, which is about 800 km southeast of Tokyo in the Ogasawara island chain.
It was moving at a speed of around 20 kph, the agency said. A maximum wind speed of 200.1 kph was measured on Chichijima, according to the agency.
The typhoon had an atmospheric pressure of 965 hectopascals and winds of up to 126 kph near its center. Winds of more than 90 kph were observed in areas within 130 km of its center, the agency said.
The Ogasawara islands were expected to see waves as high as 7 meters to 8 meters later Monday. They were also expected to get 70 mm to 100 mm of rain.