Heavy snow is forecast for Tokyo and its surrounding areas through Friday morning, with officials warning of possible traffic disruptions.

A heavy snow warning has already been issued for parts of Tokyo, along with Yamanashi, Nagano and Shizuoka prefectures, mainly in mountainous areas. The warning may be extended to include central Tokyo.

Temperatures dropped to nearly zero degrees Celsius in Tokyo's Nerima Ward on Thursday. Snow had started to accumulate on roads there around noon.

The Metropolitan Expressway Company has already closed some of its Shutoko routes as a precautionary measure to prevent vehicles from getting stranded. Officials say they may close more highways depending on the extent of the snowfall.

East Japan Railway canceled 67 limited express trains connecting Tokyo and its surrounding areas on Thursday.

And more than 200 flights were canceled, most of them leaving from or arriving at Haneda Airport.

Heavy snow is rare in the Tokyo area. Weather officials are urging people to avoid non-essential travel and stay up to date with the latest information.