Japanese weather officials say warm and damp air flowing into a front is expected to cause unstable atmospheric conditions in the Kanto Region, and heavy rains could result.

The Japan Meteorological Agency says downpours of about 40 millimeters per hour with lightning are expected in some parts of the Izu Islands, south of Tokyo, through Monday.

Up to 120 millimeters of rain is expected in the southern Kanto Region and the Izu Islands through Monday noon.

The agency says there is a possibility a warning could be issued if the rain clouds develop more than expected.

Officials are calling on people to be on the alert for possible landslides, flooding in low-lying areas and swollen rivers, as well as lightning strikes, gusty winds, including tornadoes, and hail.