Deep Freeze Grips Canada as US Records Hottest Christmas in History.
An intense cold spell has seized an intense and prolonged cold spell, with readings persisting between -20C and -40C for an extended duration. A reading of -55.7 Celsius was logged in Braeburn, Yukon, on Tuesday, its coldest December temperature since 1975.
Prolonged Freeze Below -40C
Meanwhile, Mayo and Dawson endured 16 consecutive nights colder than minus 40 degrees, with Mayo plunging to -50.4C on Monday. The capital, Whitehorse, likewise saw ten separate nights when temperatures dropped below -30C.
The deep freeze spread farther south during the holiday season. In Edmonton, the Christmas overnight low dipped under -28 degrees Celsius.
The day after Christmas was forecast to deliver minimum temperatures of at least minus 20C across many regions, including Edmonton, Montreal, Ottawa and Quebec.
Forecast to Persist into the New Year
This harsh winter weather is expected to continue into the new year. Authorities have cautioned about potential power failures in the Yukon over the next several days, as the territory’s power grid comes under strain from record-high energy demand.
The prolonged chill has been caused by the polar vortex remaining anchored over Canada for much of December, which funnels frigid northern air southward. In the coming week, forecasts indicate this cold air will pull back northward slowly, permitting warmer Pacific winds to flow over America and reach into portions of southern Canada.
Stark Contrast to American Heat
Conversely, sections of America recorded historically high temperatures for Christmas as temperatures soared about 15-30C above the seasonal average. For numerous locations, the weather resembled a spring day in April or May rather than the end of December.
A number of states broke historical records for December 25th warmth. Oklahoma City, Oklahoma, reached 25 degrees Celsius on Christmas, exceeding the old record of 22C from 1982. Metropolitan areas such as Austin, Dallas, and Charlotte similarly saw thermometers rise past the 25C mark.
Heat-Dome Effect Fuels Warmth
Unseasonable heat is predicted to persist on December 26th and into the weekend, with abnormal warmth projected to move across the southeastern US in the coming days.
The unseasonable temperatures are powered by a powerful high-altitude ridge extending from the desert south-west towards the north and east, establishing a classic heat-dome pattern. Such a configuration results in a widespread high-pressure system across much of the continent, trapping warm air near the surface. Descending air compresses and adiabatically warms, fostering the buildup of exceptional warmth.
