A low pressure system and a front are causing unstable atmospheric conditions over much of western and northern Japan.
Heavy rain and strong winds are expected in the Hokuriku region and northern Japan through Sunday.
The Meteorological Agency says the low pressure system is expected to approach eastern and northern Japan.
Intermittent thunderstorms bringing over 30 millimeters of rain per hour may hit some areas, with rainfall reaching up to 120 millimeters.
Officials warn of possible landslides, flooding in low-lying areas, swollen rivers, strong winds, high surf, lightning strikes and violent winds, including tornadoes.