[Reuters/Yonhap]
[Reuters/Yonhap]

Record-breaking rain has pounded areas across Japan, leaving at least one person dead and causing rivers to overflow. Some regions were placed under the country's highest-level disaster warning, while rail and air travel were also disrupted.

According to the Japan Meteorological Agency and public broadcaster NHK on Wednesday, a stalled autumn rain front stretching from western Japan to the Pacific coast of eastern Japan has been drawing in warm, moist air. This has worsened atmospheric instability, and as the front's activity intensifies, extremely heavy rain has continued to fall in localized areas.

Oshima, an island in the Izu Islands south of Tokyo, recorded particularly extreme rainfall. The area's maximum 48-hour precipitation reached 757.5 millimeters, the highest ever observed there for September.

Aichi and Gifu prefectures also saw heavy rain concentrated from Wednesday evening. A "linear precipitation band" — a long, narrow band of rain clouds — formed over the area, dumping large amounts of rain in a short period. The Shonai River, which runs through both prefectures, was briefly placed under a Level 5 flood warning, the special category reserved for imminent or ongoing flooding.

Japan's disaster warning system has five levels. Level 5, the highest, indicates that a disaster has already occurred or is about to occur. Residents in areas under a Level 5 warning are urged to move beyond simply deciding whether to evacuate and instead immediately secure a safe location to protect their lives.

In Nagoya, Aichi Prefecture, 104.5 millimeters of rain fell in the hour leading up to 5 p.m. Tuesday. The downpour caused the water level of the Ueda River, which runs through downtown Nagoya, to rise rapidly and overflow, flooding roads across the city and submerging vehicles.

As the rain continued, Nagoya ordered all public schools and kindergartens in the city to close temporarily Wednesday.

Other areas also saw tens of millimeters of rain per hour. Nanbu, a town in Yamanashi Prefecture, recorded 51 millimeters of rain in the hour leading up to 8 p.m. Wednesday. Hachioji in Tokyo logged 40 millimeters, while Koga in Ibaraki Prefecture recorded 38.5 millimeters per hour.

Tokyo itself was not spared. Heavy rain concentrated overnight Tuesday raised water levels in some rivers, and weather authorities are closely watching for further flooding, river overflows and landslides.

Transportation networks were also disrupted. JR lines serving the greater Tokyo area, including the Yamanote, Chuo and Sobu lines, temporarily reduced service before returning to normal operations. However, some sections of the Joban, Suigun and Hachiko lines remained suspended due to the heavy rain. Flights were also affected by the severe weather.

The Japan Meteorological Agency forecast that a tropical low-pressure system would merge with the autumn rain front and move northeast, widening the area affected by heavy rain. As a result, it said, strong rain is likely to continue across a wide swath from western Japan to the Tohoku region.

"The likelihood of warning-level heavy rain remains high in the Tokai, Kinki and Shikoku regions, as well as the Kanto-Koshin area," the agency said. It urged particular caution over landslides, flooding in low-lying areas and river overflows.


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