Environment Canada yesterday said snow was expected to move into Durham from the west just after midnight and continue until early Friday morning.
At any location, the heaviest snowfall is most likely for the first two or three hours after onset. Snow will then become mixed with or change over to rain overnight, especially near and south of Highway 401, it said.
Total snowfall amounts by early Friday morning will be around 5 cm except closer to 2 cm near the Lake Ontario shore.
Road conditions are expected to rapidly deteriorate once the snow arrives. Untreated roads may suddenly become snow covered and slippery. Motorists should allow for extra time to reach their destination. Strong winds will be a factor too.
The first part of the Friday morning commute may be affected, especially in areas where precipitation falls as all snow.