Deep Freeze Envelops the Great White North as America Sees Most Unseasonably Mild Christmas Ever.
Northern Canada has been gripped by an intense and prolonged cold spell, with readings persisting between -20C and -40C for multiple weeks. 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 in the Deep Minus Forties
In addition, the locales of Mayo and Dawson suffered through sixteen nights in a row colder than minus 40 degrees, with the temperature in Mayo bottoming out at -50.4 degrees Celsius on Monday. Whitehorse also recorded ten separate nights when readings fell to minus 30 degrees or lower.
The bitter chill extended its reach south through Christmas week. On Christmas Day, overnight temperatures in Edmonton fell below -28C.
Boxing Day was expected to bring minimum temperatures of at least minus 20C across many regions, encompassing cities from Edmonton to Quebec.
Likely to Linger For Days to Come
The frigid conditions are predicted to linger into the new year. Authorities have cautioned about potential power failures in the Yukon in the coming days, as its energy infrastructure faces unprecedented demand from peak power usage levels.
The prolonged chill has been caused by 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 gradually, enabling milder Pacific air to move across the US and into parts of southern Canada.
Stark Contrast to American Heat
Conversely, sections of America recorded the hottest December 25th in their history as readings skyrocketed 15 to 30 degrees Celsius above normal. Across wide regions, the atmosphere was more akin to late spring rather than the end of December.
Multiple states established new Christmas temperature highs. The capital of Oklahoma soared to 25C on Christmas Day, topping the prior high mark of 22 degrees established over forty years ago. Cities including Austin and Dallas, in Texas, and Charlotte, North Carolina were also among those that recorded temperatures above 25C.
Atmospheric Ridge Sustains High Temperatures
Above-average warmth is expected to continue on December 26th and into the weekend, with unseasonable heat forecast to sweep through the American Southeast soon.
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. This setup creates an extensive zone of high atmospheric pressure blanketing a significant part of the landmass, which holds warm air close to the ground. Descending air compresses and adiabatically warms, enabling abnormally high temperatures to develop.
