Arctic Blast Grips Canada as US Records Warmest Christmas Ever.
A prolonged deep freeze has enveloped an intense and prolonged cold spell, with readings persisting between -20C and -40C for weeks. This week, the Yukon community of Braeburn saw the mercury drop to -55.7C, its coldest December temperature in nearly five decades.
Enduring Chill in the Deep Minus Forties
Similarly, the communities of Mayo and Dawson experienced 16 consecutive nights colder than minus 40 degrees, with the temperature in Mayo bottoming out at -50.4 degrees Celsius earlier this week. Whitehorse also recorded a series of ten nights when readings fell to minus 30 degrees or lower.
The deep freeze spread farther south through Christmas week. 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 in numerous areas, including Edmonton, Montreal, Ottawa and Quebec.
Expected to Continue Through Early January
The severe cold is forecast to persist through the start of January. Authorities have cautioned about potential power failures in the Yukon in the coming days, as the territory’s power grid comes under strain from peak power usage levels.
The prolonged chill has been caused by a stationary polar vortex above Canadian territory through December, which funnels frigid northern air southward. The frigid dome is projected to gradually withdraw north allowing more temperate air from the Pacific to sweep across America and reach into portions of southern Canada.
Dramatic Difference to American Heat
Meanwhile, in a dramatic contrast, areas of the United States saw historically high temperatures for Christmas as the mercury climbed roughly 15 to 30 degrees above typical averages. 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. The capital of Oklahoma soared to 25C on Christmas Day, surpassing the previous peak of 22C set in 1982. Cities including Austin and Dallas, in Texas, and Charlotte, North Carolina similarly saw thermometers rise past the 25C mark.
High-Pressure System Fuels Warmth
Warmer-than-normal conditions are forecast to last on December 26th and into the weekend, with atypical high temperatures expected to spread through the American Southeast soon.
The warmth has been fuelled by a powerful high-altitude ridge stretching from the southwestern deserts northward and eastward, establishing a classic heat-dome pattern. This setup creates an extensive zone of high atmospheric pressure over a large portion of North America, effectively capping warm air at lower altitudes. Sinking atmospheric air undergoes compression and additional heating, enabling abnormally high temperatures to develop.
