Northern Kyushu was lashed with heavy downpours Monday morning, triggering a high flood risk in rivers in an around Kumamoto Prefecture, NHK television reported.
The Meteorological Agency has warned of potential landslides and river floods, adding floods may go above floor levels in low-lying areas due to the very heavy precipitation, according to NHK.
The rain stems from an unstable air mass covering wide areas of western Japan as a result of moist air flowing toward the seasonal rain front that extends from the East China Sea to Kyushu.
Very heavy downpours were observed in Amakusa, Kumamoto Prefecture, where a prefectural rain gauge recorded 51 mm of rain over an hour up to 4 a.m. Monday. In Kumamoto’s Reihokumachi, the rainfall exceeded 100 mm, NHK said.
The agency forecasts heavy rainfall in northern Kyushu and the Chugoku region until noon Monday, with possibility torrential precipitation reaching 60 mm per hour. It has also warned of lightening and strong gusts, NHK said.