Prolonged Chill Grips Canada as US Records Warmest Christmas in History.
A prolonged deep freeze has enveloped an intense and prolonged cold spell, with thermometers lingering from 20 to 40 degrees below zero for an extended duration. This week, the Yukon community of Braeburn saw the mercury drop to -55.7C, marking its chilliest December reading in nearly five decades.
Enduring Chill Below -40C
In addition, the locales of Mayo and Dawson suffered through 16 consecutive nights below -40C, with Mayo experiencing a low of -50.4C at the start of the week. Whitehorse similarly reported 10 nights when the cold dipped under -30 Celsius.
The bitter chill extended its reach south during the holiday season. Christmas night saw Edmonton's temperatures plummet below minus 28C.
Boxing Day was expected to bring lows of at least -20C across many regions, including Edmonton, Montreal, Ottawa and Quebec.
Likely to Linger Through Early January
The severe cold is forecast to persist into the new year. There are warnings of possible electrical grid strain in Yukon territory in the coming days, as the territory’s power grid comes under strain from record-high energy demand.
The lengthy cold snap originates from the polar vortex remaining anchored over Canada for much of December, which funnels frigid northern air southward. Next week, the cold air mass is expected to retreat north gradually, enabling milder Pacific air to move across America and reach into portions of southern Canada.
Pronounced Disparity with US Warmth
Meanwhile, in a dramatic contrast, areas of the United States saw historically high temperatures for Christmas as temperatures soared about 15-30C above the seasonal average. Across wide regions, the atmosphere was more akin to late spring than late December.
A number of states broke historical records for December 25th warmth. In Oklahoma, Oklahoma City hit 25C on Tuesday, topping the prior high mark of 22 degrees established over forty years ago. Metropolitan areas such as Austin, Dallas, and Charlotte were also among those that recorded temperatures above 25C.
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 warmth has been fuelled by a strong upper-level ridge reaching from the arid southwest across the continent, which generates a heat-dome phenomenon. Such a configuration results in a widespread high-pressure system across much of the continent, effectively capping warm air at lower altitudes. Sinking atmospheric air undergoes compression and additional heating, fostering the buildup of exceptional warmth.
