BARRIE, ONT. -- A snow squall watch is in effect for parts of Simcoe County, Parry Sound, Grey Bruce, and Muskoka.

Environment Canada warns motorists to prepare for hazardous, snowy conditions.

Lake-effect squalls could develop late Thursday afternoon, with the potential for up to 15 centimetres of snow accumulation before the evening.

The weather agency issued the watch for the Dufferin, Barrie, Muskoka, and Bruce County areas, including Collingwood, Midland, Bracebridge, Gravenhurst and Port Severn.

Environment Canada warns visibility may be significantly reduced or suddenly reduced to near zero on roadways.

Highways, roads, walkways, and parking lots may become difficult to navigate in the conditions.

The agency recommends drivers consider postponing non-essential travel until conditions improve.