Weather tracker: Cold air over warm waters brings heavy snow to Japan

Prefectures in north hit by falls of up to 30cm in a day as similar weather pattern affects parts of north America

Heavy snow fell across northern Japan on Thursday, with the prefectures of Hokkaido, Aomori, Yamagata and Niigata particularly affected. Accumulations of 20-30cm over a 24-hour period were recorded across the affected areas, with local totals of more than 30cm near Aomori City.

The snowfall was a result of heavy showers generated by a cold airmass moving in from the north-west across the relatively warm waters of the Sea of Japan. This resulted in warming of the lowest levels of the atmosphere, leading to rising motion and convective shower development caused by the increased moisture. Ascent was further aided by the mountainous terrain across northern Japan.