Prolonged Chill Tightens Hold on Canada as America Sees Hottest Christmas in History.
An intense cold spell has seized a severe and lengthy Arctic outbreak, with readings persisting between -20C and -40C for an extended duration. This week, the Yukon community of Braeburn saw the mercury drop to -55.7C, marking its chilliest December reading in half a century.
Prolonged Freeze of Extreme Cold
Similarly, the communities of Mayo and Dawson experienced over two straight weeks of nights below -40C, with Mayo plunging to -50.4C earlier this week. Whitehorse similarly reported 10 nights when temperatures dropped below -30C.
This Arctic air mass pushed further southward over the festive period. On Christmas Day, overnight temperatures in Edmonton fell below -28C.
The day after Christmas was forecast to deliver lows of at least -20C through a wide swath, from Edmonton in the west to Quebec in the east.
Expected to Continue For Days to Come
The frigid conditions are predicted to linger for the foreseeable future. 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 peak power usage levels.
This extended freeze is the result of the Arctic vortex settling over Canada for much of December, enabling a surge of icy Arctic winds to descend. In the coming week, forecasts indicate this cold air will pull back northward gradually, enabling milder Pacific air to move across America and reach into portions of southern Canada.
Pronounced Disparity to American Heat
Conversely, sections of America recorded their warmest Christmas Day on record as temperatures soared about 15-30C above the seasonal average. For numerous locations, the weather resembled a spring day in April or May than late December.
Multiple states established new Christmas temperature highs. Oklahoma City, Oklahoma, reached 25 degrees Celsius on Christmas, exceeding the old record of 22C from 1982. Metropolitan areas such as Austin, Dallas, and Charlotte similarly saw thermometers rise past the 25C mark.
Heat-Dome Effect Drives the Heat
Warmer-than-normal conditions are forecast to last on December 26th and into the weekend, with atypical high temperatures expected to spread across the southeastern US in the coming days.
The unseasonable temperatures are powered by a strong upper-level 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, which holds warm air close to the ground. Sinking atmospheric air undergoes compression and additional heating, enabling abnormally high temperatures to develop.
