TORONTO - Snow squalls continue to make driving a challenge on roads and highways to the east of Lake Huron and Georgian Bay and around Lake Simcoe.

Environment Canada says the latest squalls and most intense are crossing the Bruce Peninsula and running east across Orillia and toward Kawartha Lakes.

Up to 30 centimetres of snow is likely in several areas southeast of Georgian Bay with snowfall rates of five-to-10 centimetres per hour being recorded in some spots.

Road closures include Highway 21 from Dunlop to Southampton, County Road 124 in Dufferin County, Highway 6 from Tobermory to Wiarton and Highway 4 between Hensal and Clinton.

Provincial police are advising drivers to avoid all highways and country roads in Huron County because of whiteouts and drifting snow.

The snow has forced numerous school bus cancellations and closures in the Huron-Perth, Barrie, Orillia, Midland and Penetanguishene areas. Buses were also left idle this morning in area townships, including Tay, Severn, Ramara and Oro-Medonte.