A powerful typhoon was approaching eastern Japan on Wednesday and expected to bring heavy rain to Pacific coastal regions including Tokyo, Japan's weather agency said.

Slow-moving Typhoon Shanshan could cause prolonged downpours with gusty winds and increase the risk of mudslides and flooding, the Japan Meteorological Agency said.

The season's 13th typhoon could make landfall early Thursday if it shifts further west as it moves northward along the coasts of Chiba and Ibaraki prefectures, according to the agency, possibly affecting commuters in the capital region during the morning rush hours.

The influence of the typhoon was already felt Wednesday, as an 82-year-old woman in Hitachinaka, Ibaraki, fell due to a strong wind and broke her left leg.

The city government of Mobara in Chiba, east of Tokyo, issued an evacuation advisory early in the afternoon to residents throughout the city, deeming evacuation after dark as dangerous, while other local governments called on residents to be ready to evacuate.

Intense rain is expected in eastern and northeastern Japan on Thursday through the morning and late night, respectively.

The typhoon and a rainy front north of it are forecast to move northward along the Pacific coast, bringing heavy rain to Hokkaido, also on Thursday.

As of 8 p.m., Shanshan was about 140 kilometers southeast of the city of Katsuura in Chiba. The typhoon was traveling north slowly with an atmospheric pressure of 970 hectopascals at its center.

The typhoon was packing gusts of up to 180 kilometers per hour, with areas within a radius of 70 km falling into the storm zone, the agency said.

In the 24-hour period through Thursday evening, a total of up to 300 millimeters of rain is expected in the Kanto region including Tokyo, 200 mm in the northeastern region of Tohoku and 120 mm in the central region.

In the following 24-hour period, up to 100 mm of rain is forecast in Hokkaido, the country's northernmost main island, the Tohoku region in the north and the Hokuriku region in central Japan facing the Sea of Japan.

On Wednesday, All Nippon Airways and Japan Airlines canceled at least 80 domestic and international flights in total.

East Japan Railway Co. decided to reduce train services in the greater Tokyo area.