January’s jet stream drama leads to February pattern swap in Canada
The Arctic chill draining across the U.S. over the past several weeks will change course as we turn the page into February.
January featured unusual jet stream dynamics across North America, a highly amplified flow funnelling Arctic air into the central and southeastern United States, fuelling a historic winter storm and bitter cold.
DON’T MISS: Winter hasn’t been so kind to Ontario’s snowbelt regions so far
All that while Canada’s Arctic regions were significantly above normal. But transient blasts of Arctic air reminded Canadians of winter weather, especially over the past week, as much-cooler temperatures seeped into southern Ontario and other parts of Canada.
January temperature anomaly
Western Canada: Mild Pacific air before the deep freeze
Once again, the ridge of high pressure across British Columbia dominates the weather story in the West, and will be the catalyst for mild Pacific air to trek across the country.
Past seven-day temperature anomaly
By late week, the western ridge flattens while a new ridge blossoms across Alaska. That sets the stage for Arctic air from Alaska to spill into the Yukon and Northwest Territories, and surge southwards. That will lead to some of the winter’s coldest temperatures for British Columbia and Alberta.
Cold milestones to watch:
Vancouver’s coldest high this winter has been a mild 4.3°C (Dec. 4)
Kamloops’ coldest high so far was -4.4°C (Jan. 20)
Temperature pattern B.C. and the Prairies Feb. 2
Expect those marks to be challenged as some of the coldest temperatures of the season arrive by the weekend.
Eastern Canada: A gradual shift and brief respite
To those of you in Eastern Canada, the transition will feel much less abrupt.
Coldest daytime high temperatures winter 2024-25 (Jan. 26)
A lingering, upper trough stalls across northern Quebec, creating volatile weather and cold air to Ontario, Quebec and the Maritimes this week.
However, Pacific will push eastward by early February, bringing a brief reprieve from the deep chill for much of Eastern Canada.
February outlook: Active storms and volatile weather
The flip in temperature anomalies, colder air northwest of the Great Lakes and milder weather across the U.S. Southeast, sets the stage for an active storm track.
Atmospheric heights/storm track in early February
While no extended thaw is forecast, no matter what the groundhog predicts, February storms may bring the risk of rain at times as the storm track shifts north, alongside the continued threat of winter weather.
Stay tuned to The Weather Network for the latest forecast updates across Canada.
With files from Tyler Hamilton, a meteorologist at The Weather Network.
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