Weather officials in Japan are forecasting heavy rain with thunder in western Japan through Tuesday. They are calling for vigilance against landslides.
Officials of the Japan Meteorological Agency say a warm, damp air mass is flowing toward a seasonal rain front over western Japan. They say it has made atmospheric conditions very unstable in the region.
The front has brought intermittent heavy rain to southern Kyushu.
The officials say the front is expected to move south to waters off the main island of Honshu, and will then stay around southern Kyushu.
They say up to 150 millimeters of rainfall is expected for southern Kyushu in the 24 hours though Tuesday morning.
Up to 130 millimeters is expected for northern Kyushu and 80 millimeters for the Kinki region.
The officials warn that even a little more rainfall could increase landslide risks because the ground may already be saturated in some areas.
They are calling on people to be on the alert over risks of landslides, flooding in low-lying areas, swelling rivers, lightning strikes, violent gusts like tornadoes and hailstorms.
People are urged to take shelter in sturdy buildings if developed thunderstorm clouds are approaching.
The agency is also calling for people in eastern Japan and elsewhere to be vigilant against heatstroke on Monday.
Temperatures topped 35 degrees Celsius in Shizuoka City in the Tokai region in the morning. The agency says the mercury will likely soar in the Kanto region as well.
The agency and the Environment Ministry have issued a heatstroke alert for Ibaraki and Kagoshima prefectures and the Yaeyama region of Okinawa Prefecture.
People should take extra care to prevent heatstroke by using air conditioners properly, drinking water frequently, avoiding working and exercising outdoors for long periods, and resting appropriately.