Snow and bitterly cold temperatures are expected this weekend.
Environment Canada issued a special weather statement Thursday afternoon saying southwestern Ontario is expected to be on the northern fringe of a major winter storm tracking well south of the Great Lakes.
The weather agency said periods of snow will begin late Friday night and continue into Saturday evening.
Forecasters said Thursday that the latest analysis suggested snowfall amounts will range from 10 centimetres to 15 centimeters, four to six inches, near Lake Erie, to two to five centimetres north of Highway 7.
Areas close to Lake Huron are also expected to receive additional snowfall accumulations Sunday due to snow squalls.
The U.S. National Weather Service was calling for about three inches or eight centimetres of snow in the Port Huron area for Saturday.
Rapidly accumulating snow and blowing snow could make travel difficult over some locations and highway and road surfaces, walkways and parking lots may become icy and slippery.
Environment Canada said there was still much uncertainty about the storm track, and that a more northerly track would increase snowfall amounts.
Regardless of the track, bitterly cold temperatures and winds gusting to 60 km/h will accompany the snow, resulting in wind chill values in the - 20 C to -30 C range into Monday morning.
Lambton OPP are forewarning drivers.
Constable Chris Doupe said an overnight freeze Wednesday morning resulted in a half dozen minor collisions.
Drivers are encouraged to slow down and adjust to changing conditions.