Arctic Blast Envelops the Great White North as America Sees Warmest Christmas on Record.
A prolonged deep freeze has enveloped an intense and prolonged cold spell, with thermometers lingering in the minus 20 to minus 40 Celsius range for an extended duration. A reading of -55.7 Celsius was logged in Braeburn, Yukon, on Tuesday, its coldest December temperature in nearly five decades.
Enduring Chill in the Deep Minus Forties
Meanwhile, Mayo and Dawson endured over two straight weeks of nights colder than minus 40 degrees, with Mayo experiencing a low of -50.4C earlier this week. The capital, Whitehorse, likewise saw a series of ten nights when readings fell to minus 30 degrees or lower.
This Arctic air mass pushed further southward during the holiday season. Christmas night saw Edmonton's temperatures plummet below minus 28C.
The day after Christmas was forecast to deliver minimum temperatures of at least minus 20C through a wide swath, including Edmonton, Montreal, Ottawa and Quebec.
Forecast to Persist 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 in the coming days, as its energy infrastructure faces unprecedented demand from record-high energy demand.
The lengthy cold snap originates from a stationary polar vortex over Canada for much of December, which funnels frigid northern air southward. The frigid dome is projected to gradually withdraw north slowly, permitting warmer Pacific winds to flow over America and reach into portions of southern Canada.
Pronounced Disparity with US Warmth
Meanwhile, in a dramatic contrast, areas of the United States saw their warmest Christmas Day on record as readings skyrocketed 15 to 30 degrees Celsius above normal. For numerous locations, the weather resembled a spring day in April or May than late December.
Several states set Christmas Day temperature records. In Oklahoma, Oklahoma City hit 25C on Tuesday, topping the prior high mark of 22 degrees established over forty years ago. Cities including Austin and Dallas, in Texas, and Charlotte, North Carolina similarly saw thermometers rise past the 25C mark.
High-Pressure System Sustains High Temperatures
Above-average warmth is expected to continue through Boxing Day and the days ahead, with unseasonable heat forecast to sweep through the American Southeast soon.
The unseasonable temperatures are powered by a powerful high-altitude ridge reaching from the arid southwest across the continent, establishing a classic heat-dome pattern. This setup creates an extensive zone of high atmospheric pressure blanketing a significant part of the landmass, trapping warm air near the surface. Descending air compresses and adiabatically warms, allowing unusually warm temperatures to build.
