Heavy rain is forecast from western to northern Japan through Thursday.

The Meteorological Agency says humid air is flowing into a front stretching from the Sea of Japan to eastern Japan. It says this is causing atmospheric conditions to become unstable in wide areas from western to eastern Japan.

Rain clouds were developing over northern Kyushu, Kansai, Tokai and other areas in western and eastern Japan on Wednesday evening. The Saikai city of Nagasaki prefecture had 37 millimeters of rainfall in an hour from 7 p.m. to 8 p.m.

Mudslide warnings have been issued in some areas of Fukuoka and Saga prefectures.
Downpours and lightning are forecast in western and eastern Japan until Thursday, due to the effects of the front moving south.

Some areas may have extremely heavy precipitation of over 50 millimeters an hour. Officials say areas along the Japan Sea coast in western Japan could have more than 80 millimeters an hour.

A low pressure system accompanied by the front is expected to approach the Tohoku region, which recently had record heavy rainfall.

The maximum rainfall forecast for the 24 hours until late Thursday afternoon is 180 millimeters in northern Kyushu, and 150 millimeters in the Shikoku and Tohoku regions. The Chugoku, Kansai, Tokai and Hokuriku regions and Niigata Prefecture are expected to see 120 millimeters. The Kanto-Koshin region is expected to get 100 millimeters.

The rain is expected to hit during a relatively short time.

Officials are warning of mudslides, flooding in low-lying areas, swelling river.