The Japan Meteorological Agency issued a heavy rain emergency warning for Yamagata Prefecture for the second time in the space of a day on Thursday.
The warning is the highest level on the country’s five-tier alert scale, and urges people to exercise maximum caution over rivers bursting their banks, flooding and mudslides.
The latest emergency warning was issued at 11:40 p.m. on Thursday. It covers the cities of Sakata and Shinjo, the towns of Funagata and Shonai and the villages of Sakegawa and Tozawa.
JMA officials say an active seasonal rain front has brought record downpours to the northeastern prefectures of Yamagata and Akita.
Bands of clouds that cause torrential rain developed over some areas of Yamagata Prefecture, prompting agency officials to issue a bulletin on significant rainfall.
The Nikko River, which runs through Sakata City in Yamagata, overflowed, as did the Koyoshi River in Akita’s Yurihonjo City.
Overflowing warnings are in place for the Sakegawa, Mogamioguni, Oyama, Aizawa and Nyuu rivers as well as the middle and lower reaches of the Mogami River — all in Yamagata Prefecture. Some other rivers in Yamagata and Akita prefectures are also above overflowing warning levels.
A mudslide alert is in effect for some parts of Yamagata, Akita, Miyagi and Iwate prefectures.
Total expected precipitation for the 24-hour period through Friday night could reach 150 millimeters in northeastern Japan. Even more rain is expected for the region after that.
People in rain-hit areas should move to higher floors in their homes if they feel it is too dangerous to flee to evacuation shelters. In that case, they say it will be safer to stay in rooms facing away from mountain slopes.
The meteorological agency had issued a heavy rain emergency warning for Sakata City and Yuza Town in Yamagata Prefecture shortly after 1 p.m. on Thursday, before downgrading it to a warning in the evening.