Environment Canada is warning of snow squalls set to hit parts of southern and northern Ontario that could bring up to 60 centimetres of snow to some regions.
The weather agency has issued alerts for several regions in southern Ontario, including Barrie, Parry Sound-Muskoka, Niagara and Kingston-Prince Edward County.
It says snow squalls could form off Lake Huron, Lake Ontario, Lake Erie and Georgian Bay Thursday night through Sunday for extended periods.
Local snowfall amounts range from 15 to 25 cm by Friday afternoon in Barrie, to 30 to 60 cm by Sunday in other regions, including Simcoe, Grey-Bruce and Niagara.
The weather agency has also issued a snow squall alert for Lake Nipigon-Wabakimi in northern Ontario, saying 15cm to 20 cm could arrive by Friday afternoon.
It says visibility may be reduced to near zero in some regions of the province due to heavy and blowing snow.