Deep Freeze Grips the Great White North as America Sees Most Unseasonably Mild Christmas in History.
Northern Canada has been gripped by an intense and prolonged cold spell, with thermometers lingering in the minus 20 to minus 40 Celsius range for an extended duration. On Tuesday, Braeburn in the Yukon recorded -55.7C, its coldest December temperature in half a century.
Prolonged Freeze of Extreme Cold
Similarly, the communities of Mayo and Dawson experienced sixteen nights in a row dipping under the minus 40 Celsius threshold, with the temperature in Mayo bottoming out at -50.4 degrees Celsius at the start of the week. Whitehorse also recorded ten separate nights when readings fell to minus 30 degrees or lower.
The deep freeze spread farther south over the festive period. On Christmas Day, overnight temperatures in Edmonton fell below -28C.
December 26th was anticipated to usher in lows of at least -20C through a wide swath, from Edmonton in the west to Quebec in the east.
Forecast to Persist into the New Year
The frigid conditions are predicted to linger 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 lengthy cold snap originates from the polar vortex remaining anchored over Canada for much of December, enabling a surge of icy Arctic winds to descend. Next week, the cold air mass is expected to retreat north gradually, enabling milder Pacific air to move across the US and into parts of southern Canada.
Dramatic Difference with US Warmth
Meanwhile, in a dramatic contrast, areas of the United States saw their warmest Christmas Day on record 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 instead of the heart of winter.
A number of states broke historical records for December 25th warmth. 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
Unseasonable heat is predicted to persist on December 26th and into the weekend, with unseasonable heat forecast to sweep into the south-eastern states later in the week.
The unseasonable temperatures are powered by a strong upper-level ridge extending from the desert south-west towards the north and east, which generates a heat-dome phenomenon. This setup creates an extensive zone of high atmospheric pressure blanketing a significant part of the landmass, which holds warm air close to the ground. Sinking atmospheric air undergoes compression and additional heating, fostering the buildup of exceptional warmth.
