Arctic Blast Tightens Hold on Canada as America Sees Most Unseasonably Mild Christmas on Record.
A prolonged deep freeze has enveloped an intense and prolonged cold spell, with thermometers lingering between -20C and -40C for weeks. On Tuesday, Braeburn in the Yukon recorded -55.7C, marking its chilliest December reading in nearly five decades.
Consecutive Nights in the Deep Minus Forties
Similarly, the communities of Mayo and Dawson experienced 16 consecutive nights dipping under the minus 40 Celsius threshold, with the temperature in Mayo bottoming out at -50.4 degrees Celsius on Monday. The capital, Whitehorse, likewise saw ten separate nights when the cold dipped under -30 Celsius.
The deep freeze spread farther south through Christmas week. On Christmas Day, overnight temperatures in Edmonton fell below -28C.
December 26th was anticipated to usher in lows of at least -20C across many regions, from Edmonton in the west to Quebec in the east.
Expected to Continue into the New Year
The frigid conditions are predicted to linger through the start of January. Officials have warned that the Yukon could face electricity outages over the next several days, as its energy infrastructure faces unprecedented demand from peak power usage levels.
The lengthy cold snap originates from the polar vortex remaining anchored over Canada for much of December, enabling a surge of icy Arctic winds to descend. Next week, the cold air mass is expected to retreat north slowly, permitting warmer Pacific winds to flow over the United States and penetrate southern Canadian regions.
Dramatic Difference Compared to Stateside Temperatures
Meanwhile, in a dramatic contrast, areas of the United States saw the hottest December 25th in their history as readings skyrocketed 15 to 30 degrees Celsius above normal. In many areas, conditions felt more typical of April or May than late December.
Multiple states established new Christmas temperature highs. Oklahoma City, Oklahoma, reached 25 degrees Celsius on Christmas, topping the prior high mark of 22 degrees established over forty years ago. Urban centers like Austin, Dallas, and Charlotte, North Carolina similarly saw thermometers rise past the 25C mark.
Atmospheric Ridge Fuels Warmth
Unseasonable heat is predicted to persist through Boxing Day and the days ahead, with unseasonable heat forecast to sweep across the southeastern US in the coming days.
The unseasonable temperatures are powered by a strong upper-level ridge reaching from the arid southwest across the continent, establishing a classic heat-dome pattern. This pattern establishes a broad area of high pressure over a large portion of North America, trapping warm air near the surface. As air sinks through the atmosphere, it compresses and heats further, fostering the buildup of exceptional warmth.
