Environment Canada has issued a winter storm watch for the Barrie, Orillia, and Midland areas, with a storm expected late Wednesday into Thursday.
The national weather agency said the area could see heavy snow and ice pellets at times.
It also warned that there may be reduced visibility due to heavy snow and blowing snow for people going outside or driving.
The storm is the result of a Colorado low bringing a wintry mix of snow and ice pellets to much of southern Ontario.
The weather agency warned that heavy precipitation may lead to hazardous winter travel conditions, which may also be mixed with freezing rain in some areas.