Snow fell in parts of northern and western Japan facing the Sea of Japan as a cold air mass blew into the archipelago Tuesday, with flights canceled and the weather agency warning of heavy snow in other areas and traffic disruption due to frozen roads.

Wide areas of the country, including the Pacific side, could see heavy snowfall from Tuesday evening to Wednesday, as low-pressure systems near Hokkaido and south of Japan will bring the coldest air of this winter, making atmospheric conditions extremely unstable, the Japan Meteorological Agency said.

As the strong winter patterns are expected to take hold through Thursday, some parts of the country could see their lowest temperatures in a decade, leading to a possibility of snowfall in Tokyo and Osaka, the agency said.

The two major cities, as well as Fukuoka in southwestern Japan, are forecast to see subzero temperatures Wednesday morning, raising fears of frozen water pipes and icy road surfaces in the metropolitan areas.

Snowfall was observed in Fukuoka and Kagoshima on Tuesday as temperatures dropped.

Japan Airlines Co. and All Nippon Airways Co. canceled more than 120 flights to and from airports facing the Sea of Japan.

At JR Aomori Station in the northeastern prefecture of Aomori, a 43-year-old company employee, on a business trip from neighboring Iwate, said, "I will be careful of unexpected road closures and act quickly."

In the 24 hours through 6 a.m. Wednesday, the Hokuriku region in central Japan could see up to 90 centimeters of snowfall, while there may be up to 70 cm in Kanto-Koshin in eastern and central Japan and the Kinki and Chugoku regions in western Japan.

Up to 60 cm of snow is expected in northeastern Tohoku and central Tokai regions, the agency said.