Environment Canada said a winter storm is expected to come into part of Simcoe County in southern Ontario Friday night.
The national weather agency said Thursday a winter weather watch is in effect for Barrie, Midland and Orillia.
Environment Canada is predicting significantly reduced visibility due to heavy and blowing snow due to strong winds.
It expects between 15 and 20 centimetres of snow will fall between Friday evening and Saturday morning.
The weather agency said the rapidly accumulating snowfall will create hazardous travel conditions.
The storm system is the result of a Texas low that is expected to bring heavy snow and strong winds to a large swath of southern Ontario.
As of Thursday, the weather agency said there remains some uncertainty as to where the heaviest snowfall will take place and that winter storm warnings or snowfall warnings may be issued as the event draws nearer.