Arctic Blast Grips the Great White North as US Records Hottest Christmas Ever.
A prolonged deep freeze has enveloped an intense and prolonged cold spell, with readings persisting in the minus 20 to minus 40 Celsius range for multiple weeks. On Tuesday, Braeburn in the Yukon recorded -55.7C, representing its most frigid December day in half a century.
Prolonged Freeze of Extreme Cold
In addition, the locales of Mayo and Dawson suffered through 16 consecutive nights dipping under the minus 40 Celsius threshold, with Mayo experiencing a low of -50.4C earlier this week. The capital, Whitehorse, likewise saw ten separate nights when readings fell to minus 30 degrees or lower.
This Arctic air mass pushed further southward 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 in numerous areas, from Edmonton in the west to Quebec in the east.
Likely to Linger Through Early January
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 peak power usage levels.
The lengthy cold snap originates from the Arctic vortex settling over Canada for much of December, enabling a surge of icy Arctic winds to descend. The frigid dome is projected to gradually withdraw north allowing more temperate air from the Pacific to sweep across the United States and penetrate southern Canadian regions.
Dramatic Difference with US Warmth
Conversely, sections of America recorded their warmest Christmas Day on record as the mercury climbed roughly 15 to 30 degrees above typical averages. In many areas, conditions felt more typical of April or May instead of the heart of winter.
Multiple states established new Christmas temperature highs. The capital of Oklahoma soared to 25C on Christmas Day, surpassing the previous peak of 22C set in 1982. Urban centers like Austin, Dallas, and Charlotte, North Carolina also logged readings above 25 degrees Celsius.
Heat-Dome Effect Fuels Warmth
Above-average warmth is expected to continue for the remainder of the week and beyond, with abnormal warmth projected to move through the American Southeast soon.
The warmth has been fuelled by a strong upper-level 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 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.
