Thousands of people on the southern Japanese island of Kyushu have fled their homes as Typhoon Nabi blows in, injuring at least 10 people.
Winds have eased slightly, but are still reaching 144km/h (89mph), with some areas getting 800mm (32 inches) of rain in 24 hours.
At least one person died as a result of heavy rains ahead of the typhoon.
It follows Typhoon Talim which battered Taiwan and China last week, killing more than 80 people in eastern China.
About 10% of Japan's population lives on Kyushu. More than 70,000 people have been advised to evacuate.
Seventy troops have been deployed to the island, reports BBC.
According to Reuters, the typhoon, named Nabi, meaning "butterfly" in Korean, was moving north at 25 km an hour (16 mph) but was forecast to swing east and beat a path up the Japan Sea coast, bringing rain and strong winds to western Japan and parts of South Korea before hitting the northernmost main Japanese island of Hokkaido. It was not expected to hit China.
Airlines in South Korea cancelled dozens of domestic and international flights on Tuesday because of the weather and ships were warned to stay in port.
Television showed roads deep under water in the Kyushu city of Kagoshima and waves engulfing coastal roads on the island, which has a mixture of heavy industry and agriculture.
The slow pace at which the typhoon is moving means that further heavy rains are expected before it moves on.
Hundreds of flights and ferries in and out of Kyushu and the neighbouring main island of Shikoku were cancelled because of high winds. All West Japan Railway Co. train services in Kyushu were halted at one point during the morning, Kyodo
About 270,000 households were without electricity at 11 a.m., according to Kyushu Electric Power.