Torrential rain and thunderstorms may hit parts of northern Japan by Monday night.

Japanese weather officials say atmospheric conditions from the country's north to east are unstable and rain clouds are developing in limited areas in northern and central Japan.

In the 24-hour period to Tuesday noon, up to 120 millimeters of rain is expected in the northern prefecture of Hokkaido.

Extremely strong winds will blow in parts of Hokkaido and the Tohoku region on Monday. Weather officials are forecasting strong winds of up to about 80 kilometers per hour, with maximum gusts of 126 kilometers per hour.

Extremely rough seas are also forecast for some areas.

Weather officials are urging caution against landslides, flooding in low-lying areas, swelling rivers, violent winds and high waves in locations where large amounts of rain are expected. The officials are also advising people in the Kantokoshin and Tokai regions to stay alert for lightning and gusts.