Weather officials are warning that more rain will fall in northeastern Japan's Tohoku region and neighboring Niigata Prefecture late Wednesday and Thursday.

They are calling on people to be vigilant for possible swollen rivers and mudslides, as soil and river banks have been loosened due to continued rain.

The Meteorological Agency says warm and moist air is flowing toward a low-pressure system in the Sea of Japan and an accompanying front, making atmospheric conditions unstable from Tohoku to Kyushu.

Some parts of the flood-hit northeastern prefecture of Akita received more than 150 millimeters of rain in the 24 hours through Wednesday evening. Officials warn of a high risk of mudslides in some areas of the prefecture.

In Niigata Prefecture, located on the Sea of Japan side, 31 millimeters of rain was observed in Murakami City during the hour through 5 p.m.

The Meteorological Agency says that in the Tohoku region, thunderstorms will bring localized torrential rain through Thursday. In Niigata and the Hokuriku region, thunderstorms may continue for several more hours on Wednesday.

The agency says that during the 24 hours through Thursday evening, rainfall is forecast to reach up to 150 millimeters in Tohoku, 80 millimeters in Niigata Prefecture and the Kanto region and 50 millimeters in the Hokuriku region.

Weather forecasters say that due to loosened soil, even a small amount of additional rain could cause disasters.
They are calling on residents to be on alert for mudslides, swollen rivers and flooding in low-lying areas.

Meanwhile, the heat wave continued over wide areas of Japan on Wednesday.

The daytime high was 37.2 degrees Celsius in Chiba Prefecture's Mobara and Ichihara, 34.8 degrees in Nagoya City, 34.1 degrees in Osaka City and 33.9 degrees in central Tokyo.

Officials are urging people to keep hydrated and use air conditioners appropriately to avoid heatstroke.