David Phillips, an Environment Canada meteorologist, said the "major weather system" bringing freezing rain and snowstorms would linger for another 18 hours.
But, he said, "it's not going to bring out the army.
"The best thing about Canadian weather is that it hits and runs." Dozens of flight cancellations and delays were reported yesterday in Ottawa, Toronto and Montreal as Environment Canada issued winter storm warnings from southwestern Ontario through to Fredericton.
About 200 flights had been cancelled at Pearson Airport.
Airports in Edmonton, Calgary and Vancouver reported delays for flights leaving to and from central Canada.
Many school boards cancelled bus service, particularly in the rural areas around Ottawa and Toronto.
Motorists in Ottawa, now on the 50th day of the city's transit strike, were being cautioned by police to drive slowly during the afternoon commute when the snowfall is expected to be heaviest.
By 5 p.m., 117 collisions had been reported on Ottawa roads, a "fairly high" number for a January evening, police said. Traffic was snarled throughout the national capital.
Similar traffic conditions were reported in Montreal, with the downtown core characterized as "chaos." The city was hit with three different warnings as well: winter storms, blowing snow and a smog alert.
The latest snowfall could lead to flooding in the city's suburbs, after the water level of the Riviere des Prairies rose on Monday due to the deep cold last week.
Homes in Laval would be threatened if the river were to break its banks.
The system is expected to wallop much of Quebec before setting its sights on the Maritimes.