The “catastrophic” winter storm that gridlocked traffic, left flights cancelled, and knocked out power in the East Coast, has pushed into eastern Canada.
As much as 24in was expected to fall in some areas by the end of Friday, blown about by heavy winds from Quebec to Newfoundland.
Authorities closed a 124 mile section of the Trans-Canada Highway in Quebec.
The storm has been blamed for the deaths of more than two dozen people.
In the US, about half a million of people and businesses remained without power in the typically mild southern states on Friday, some for a third day, after the storm destroyed power lines and knocked down trees.
The weather system tapered off as it crawled farther north, but was still strong enough to bring almost 30cm of snow to areas of Quebec and parts of Newfoundland on Friday, with high winds of more than 60 mph.
Other parts of the eastern provinces and Nova Scotia saw heavy rain from the same storm.
In eastern Quebec, several motorways, including the Trans-Canada Highway from Quebec City to Riviere-du-Loup, were partially shut after the snow and high winds dangerously hindered visibility.
Canadian weather officials have issued a number of winter storm warnings as another unrelated system is expected to bring severe weather to the Atlantic Provinces again on Saturday and Sunday.
The storm struck first on Wednesday in the US South, where it covered trees and power lines with as much as an inch of ice and caused traffic jams across the region.
South Carolina Governor Nikki Haley compared the damage to the aftermath of a hurricane.
One electric co-operative in the state lost 50 poles in the ice storm, compared to 21 in the last cyclone, officials said. Those still in the dark in the US South may wait several more days before electricity is restored.
The storm then moved up the East Coast, dumping heavy snow from North Carolina to Boston over a 24-hour period. Parts of New York state saw as much as 27in.
Washington-area offices of the US federal government were closed on Thursday to spare workers the dangerous commute.
At least 25 deaths have been blamed on the storm.
In the US, road conditions remained treacherous in some areas on Friday. Thirty people were injured, five severely, in a multiple vehicle pile-up near Philadelphia on Friday morning.
Officials said it would take many hours to clear damaged vehicles, including lorries. The crash spawned a traffic jam stretching for 5 miles.
Many schools remained closed in eight states from Virginia to Maine. Almost 1,700 flights were cancelled on Friday, and 6,500 a day earlier.
The foul weather also has delayed tens of thousands of deliveries of Valentine’s Day flowers.
Meanwhile, a sheriff in north-eastern Georgia declared in an apparently tongue-in-cheek Facebook post that the weather had rendered the Oconee County region a “No Valentines [sic] Day Zone”.
Sheriff Scott Berry declared all men in the area were exempt from having to buy chocolate or other gifts for their partners until next Tuesday.
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