Weather officials are forecasting torrential downpours accompanied by thunder mainly for western Japan through Friday. They are advising people to stay on the alert for landslides and flooding in low-lying areas.

Japan's Meteorological Agency says atmospheric conditions are very unstable over western Japan due to warm, damp air flowing toward a rain front near the country's main island.

From the predawn hours until before noon on Thursday, the Chugoku and Kinki regions saw rainfall intensify.

In the 12-hour period through 5:30 a.m. on Thursday, 234 millimeters of rain fell in Shimonoseki City in Yamaguchi Prefecture, a record since the weather agency began keeping statistics.

Kushimoto Town in Wakayama Prefecture had 95 millimeters of rain between 8 a.m. and 9 a.m.

The rain front is forecast to remain stationary through Friday. A low-pressure system is likely to move eastward, causing unstable atmospheric conditions to continue from western to eastern Japan and bringing localized torrential downpours mainly to western Japan.

In the 24-hour period through Friday evening, rainfall of up to 150 millimeters is forecast in the Kyushu region. The Kinki region is expected to have up to 120 millimeters of rain. Up to 100 millimeters of rain is likely in the Kanto-Koshin region.

Weather officials warn that even a small amount of rain could trigger disasters in the regions that have had downpours, as the ground is saturated.

Weather officials are urging caution against landslides, flooding in low-lying areas, swollen rivers, as well as lightning with gusty winds, including tornadoes, and hail.

They advise people to take shelter inside sturdy buildings in case signs of a thunderstorm appear, such as cool winds blowing and towering cumulonimbus clouds approaching.