A storm blasted heavy snow through central Ontario Friday, and was expected to bury some areas waist-deep overnight, forcing the closure of a major highway.

A snow squall warning was in effect through much of the region east of Lake Huron and the Georgian Bay Friday evening. Strong, cold westerly winds coming off the lake were generating whiteout conditions, Environment Canada reported.

West Parry Sound OPP closed a section of Highway 400 until further notice due to deteriorating weather and road conditions.

The stormy winter weather was forecast to be most severe and persistent from Manitoulin Island across Southern Georgian Bay over the Bracebridge-Gravenhurst areas into southern Haliburton county, where accumulations of another 30 centimetres were expected overnight, piling on top of the heavy drifts that already blanket the area.

By Friday morning, Ontario Provincial Police had already reported accumulations of up to 50 centimetres in some areas, and many school boards cancelled their bus services.

Police were also asking motorists to stay off the roads in the Gravenhurst and Bracebridge areas because of the intense winter storm. Police also closed some roads in southwestern Ontario and on the Bruce Peninsula because of dangerous winter conditions.

With files from the Canadian Press