A winter storm watch is in effect for the Barrie, Orillia, Midland and Collingwood areas.
Environment Canada issued the watch on Monday, saying a winter storm, with a combination of snow, ice pellets, freezing rain and strong winds, is expected to hit the region on Tuesday.
Officials say snow will begin early Tuesday morning and will mix with or change to ice pellets later Tuesday afternoon.
Total snowfall and ice pellet amounts between 15 and 25 centimetres are possible, Environment Canada says.
WATCH: How southern Ontarians can brace for another dump of snow
The weather agency says the inclement weather is associated with a Colorado low that will cross southern Ontario Tuesday and Wednesday.
Officials say heavy snow and strong easterly winds gusting to 80 km/h will cause reduced visibility, making travel hazardous.
“Surfaces such as highways, roads, walkways and parking lots may become icy and slippery,” Environment Canada said. “Poor weather conditions may contribute to transportation delays.”
Officials warn there may also be localized power outages as a result of the storm.
Comments