TOKYO, Oct. 3 (Xinhua) -- Typhoon Mitag since lashing western Japan with torrential rain has been downgraded to an extratropical cyclone, the weather agency here said Thursday, although the powerful storm is still packing strong winds as it travels across the Sea of Japan.

According to the Japan Meteorological Agency (JMA), regions in central and northern Japan, including the Hokuriku and Tohoku regions are likely to be hit by the cyclone, with the agency warning of possible flooding and landslides in the coming 24-hours.

The affected regions could experience winds of up to 126 kilometers per hour on Friday, which could cause wave surges of up to 6 meters, the JMA said.

Warmer air converging with moist conditions will also likely cause torrential rain to pummel areas on the Pacific coast in eastern Japan, the weather agency also said.

Up to 150 mm of rain is expected in the Kinki and Tokai regions in western and central Japan, the agency said, in the 24-hour period through 6 p.m. on Friday.

On the western island of Shikoku, 120 mm of rain per hour was logged on Thursday morning in some areas, according to the JMA.

In the city of Kochi, 20 cars were left submerged in a parking lot following a river bursting its banks, local officials said, although no casualties have been reported.