Deep Freeze Grips the Great White North as United States Experiences Hottest Christmas in History.
An intense cold spell has seized an intense and prolonged cold spell, with readings persisting from 20 to 40 degrees below zero for multiple weeks. A reading of -55.7 Celsius was logged in Braeburn, Yukon, on Tuesday, marking its chilliest December reading since 1975.
Enduring Chill of Extreme Cold
Meanwhile, Mayo and Dawson endured over two straight weeks of nights 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 temperatures dropped below -30C.
This Arctic air mass pushed further southward through Christmas week. In Edmonton, the Christmas overnight low dipped under -28 degrees Celsius.
The day after Christmas was forecast to deliver readings no higher than -20 Celsius in numerous areas, encompassing cities from Edmonton to Quebec.
Forecast to Persist For Days to Come
The frigid conditions are predicted to linger into the new year. There are warnings of possible electrical grid strain in Yukon territory in the coming days, as its energy infrastructure faces unprecedented demand from historically high electricity consumption.
The prolonged chill has been caused by the polar vortex remaining anchored across the northern part of the continent this month, allowing bitter Arctic air to spill south. The frigid dome is projected to gradually withdraw north slowly, permitting warmer Pacific winds to flow over the United States and penetrate southern Canadian regions.
Stark Contrast to American Heat
In stark contrast, parts of the US experienced historically high temperatures for Christmas 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.
A number of states broke historical records for December 25th warmth. Oklahoma City, Oklahoma, reached 25 degrees Celsius on Christmas, surpassing the previous peak of 22C set in 1982. Metropolitan areas such as Austin, Dallas, and Charlotte similarly saw thermometers rise past the 25C mark.
Heat-Dome Effect Fuels Warmth
Unseasonable heat is predicted to persist through Boxing Day and the days ahead, 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 extending from the desert south-west towards the north and east, establishing a classic heat-dome pattern. This pattern establishes a broad area of high pressure across much of the continent, effectively capping warm air at lower altitudes. Sinking atmospheric air undergoes compression and additional heating, fostering the buildup of exceptional warmth.