One extreme to another: Canada's temperature flip-flops this weekend

Environment Canada has issued extreme cold warnings for most of Canada, but forecasters predict the cold snap will not stick around.

The cold warnings Thursday affect portions of northern B.C., all of Alberta, as well as Saskatchewan, the southern half of Manitoba, northern Ontario and Quebec, Newfoundland and Labrador and parts of the territories.

Extreme cold warnings include wind chill values from -40 degrees Celsius in Alberta, to -55 degrees Celsius in Nunavut.

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"We've got this cold Arctic air settled right over much of Canada and so when the cloud disappears – clouds act as an insulating factor in the lower atmosphere – when you lose that, the temperature will fall," CTV's Your Morning chief meteorologist Kelsey McEwen said on Thursday.

Over the weekend, McEwen said, temperatures are forecast to rise starting in Vancouver where temperatures hovering just below zero Thursday are forecast to hit 2 degrees Celsius by Saturday.

The Prairies, McEwen says, will have temperatures in the minus single digits by Saturday afternoon, with Manitoba warming slower and rising to -10 degrees by Sunday.

"For northern Ontario, we see this trend upwards, as well as portions of Quebec but in the south, that's where things start to change," McEwen said.

Due to added cloud coverage and moisture in the air from a Colorado low in southern Ontario and Quebec, the provinces will see freezing drizzle Thursday. As the storm system passes to the East Coast, the cold "moves in."

"In terms of temperature, we'll see that the next couple of days it's pretty cool as we head into Friday, Saturday," McEwen said for southern Ontario and Quebec. "Temperatures are significantly colder than they have been (but) there is improvement by Sunday, Toronto's back above zero so it's short-lived."

As the Colorado low storm system travels to the Atlantic provinces, cool air will follow over this weekend.

"So a tale of two stories, half the country's improving, half the country is still quite cold as this polar Arctic air continues to dominate," McEwen said.