A snow squall watch is in effect for Barrie, Collingwood and Hillsdale, according to Environment Canada.
Snow squalls are predicted to develop off Georgian Bay and Lake Huron late Thursday morning through Friday afternoon.
Environment Canada says the squalls will become more organized and intensify as the winds shift to the north Thursday afternoon.
The most intense bands will likely persist through Thursday night, with conditions improving through Friday.
Environment Canada says strong winds may accompany the bands, resulting in blowing snow at times.
Total local snow accumulations of 20 to 30 cm are possible by Friday morning.
Travel may be hazardous due to the sudden changes in weather, and visibility could be suddenly reduced at times in heavy snow. Road closures are possible.