Heavy rains are pounding western Japan and the Hokuriku region on the Sea of Japan coast, due to the effects of a seasonal rain front.

Weather officials are urging people in these regions to watch out for mudslides, flooding and overflowing rivers through Friday evening.

The officials also say the front is expected to move northward, raising the risk of torrential rain in the Tohoku region in the northeast from Saturday to Sunday.

The Meteorological Agency says the atmospheric conditions over eastern Japan and the Sea of Japan side of western Japan have become extremely unstable due to the front and a cold air mass.

The city of Shobara in Hiroshima Prefecture recorded 54 millimeters of rain in the hour to 5 p.m. on Thursday.

Developed rain clouds are causing intermittent downpours on the Sea of Japan side.

The Ketaka area of Tottori City in Tottori Prefecture had 90 millimeters of rain in one hour on Thursday morning.

In Toyama Prefecture, Uozu City had an estimated 110 millimeters in the hour to 3 p.m. Toyama City recorded 193.5 millimeters of rain in the 24 hours to just before noon on Thursday, while Tonami City had 176 millimeters. Both figures are record highs.

Weather officials are warning of high risks of mudslides for some areas in Toyama Prefecture. They also warn that some rivers in Kyoto Prefecture have risen to dangerous levels.

They say the front is expected to move slowly to the north and linger over northern Japan on Saturday.

They say atmospheric conditions will be unstable in the Hokuriku region through Friday and on the Sea of Japan side of the Tohoku region from Saturday, possibly causing torrential downpours.

The officials are warning of the risks of mudslides, flooding in low-lying areas and overflowing rivers. They are also calling on people to be vigilant for lightning strikes, gusty winds and tornadoes, sudden downpours and hailstorms.