Weather officials are warning of torrential rain in the Tohoku region and eastern Japan through Thursday and in the western Japan through Friday.
These areas are expected to be intermittently hit by downpours accompanied by thunder.
Japan’s Meteorological Agency says atmospheric conditions are expected to be unstable in wide areas from the Tohoku region to western Japan due to a seasonal rain front stretching from the Sea of Japan to northern Japan and warm, damp air flowing toward the rain front.
In the 24-hour period through Thursday morning, up to 150 millimeters of rain is forecast in the Tohoku, Tokai and Chugoku regions.
The Hokuriku region is expected to see as much as 120 millimeters of rain. Up to 100 millimeters of rain is likely in northern Kyushu.
During the 24-hour period through Friday morning, up to 100 millimeters of rain is expected in northern Kyushu, 80 millimeters in the Hokuriku and Chugoku regions and 50 millimeters in the Tohoku region.
The meteorological agency is urging caution against flooding in low-lying areas, landslides, swollen rivers, as well as lightning, gusting wind, including tornadoes, and hail.