Deep Freeze Tightens Hold on Canada as America Sees Hottest Christmas Ever.
A prolonged deep freeze has enveloped a bitter and extended period of frigid weather, with readings persisting between -20C and -40C for weeks. On Tuesday, Braeburn in the Yukon recorded -55.7C, representing its most frigid December day since 1975.
Enduring Chill of Extreme Cold
Similarly, the communities of Mayo and Dawson experienced over two straight weeks of nights colder than minus 40 degrees, with Mayo plunging to -50.4C on Monday. The capital, Whitehorse, likewise saw ten separate nights when the cold dipped under -30 Celsius.
The bitter chill extended its reach south over the festive period. In Edmonton, the Christmas overnight low dipped under -28 degrees Celsius.
December 26th was anticipated to usher in lows of at least -20C in numerous areas, from Edmonton in the west to Quebec in the east.
Expected to Continue into the New Year
The frigid conditions are predicted to linger through the start of January. Officials have warned that the Yukon could face electricity outages soon, as the system endures record-high pressure from record-high energy demand.
The prolonged chill has been caused by a stationary polar vortex over Canada for much of December, enabling a surge of icy Arctic winds to descend. The frigid dome is projected to gradually withdraw north gradually, enabling milder Pacific air to move across the United States and penetrate southern Canadian regions.
Dramatic Difference to American Heat
In stark contrast, parts of the US experienced the hottest December 25th in their history as temperatures soared about 15-30C above the seasonal average. Across wide regions, the atmosphere was more akin to late spring 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. Metropolitan areas such as Austin, Dallas, and Charlotte also logged readings above 25 degrees Celsius.
Heat-Dome Effect Drives the Heat
Above-average warmth is expected to continue for the remainder of the week and beyond, with unseasonable heat forecast to sweep into the south-eastern states later in the week.
The unseasonable temperatures are powered by a robust atmospheric ridge stretching from the southwestern deserts northward and eastward, creating a heat-dome effect. 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, fostering the buildup of exceptional warmth.
