Arctic Blast Envelops Canada as US Records Hottest Christmas Ever.
An intense cold spell has seized an intense and prolonged cold spell, with readings persisting from 20 to 40 degrees below zero for an extended duration. On Tuesday, Braeburn in the Yukon recorded -55.7C, representing its most frigid December day in half a century.
Enduring Chill in the Deep Minus Forties
In addition, the locales of Mayo and Dawson suffered through 16 consecutive nights dipping under the minus 40 Celsius threshold, with Mayo plunging to -50.4C at the start of the week. Whitehorse similarly reported 10 nights when temperatures dropped below -30C.
The deep freeze spread farther 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, including Edmonton, Montreal, Ottawa and Quebec.
Forecast to Persist into the New Year
The frigid conditions are predicted to linger for the foreseeable future. Officials have warned that the Yukon could face electricity outages over the next several days, as its energy infrastructure faces unprecedented demand from record-high energy demand.
The lengthy cold snap originates from the Arctic vortex settling over Canada for much of December, allowing bitter Arctic air to spill south. 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 the mercury climbed roughly 15 to 30 degrees above typical averages. For numerous locations, the weather resembled a spring day in April or May than late December.
Several states set Christmas Day temperature records. Oklahoma City, Oklahoma, reached 25 degrees Celsius on Christmas, topping the prior high mark of 22 degrees established over forty years ago. Cities including Austin and Dallas, in Texas, and Charlotte, North Carolina were also among those that recorded temperatures above 25C.
Heat-Dome Effect Sustains High Temperatures
Warmer-than-normal conditions are forecast to last through Boxing Day and the days ahead, with unseasonable heat forecast to sweep through the American Southeast soon.
The unseasonable temperatures are powered by a robust atmospheric ridge extending from the desert south-west towards the north and east, establishing a classic heat-dome pattern. This setup creates an extensive zone of high atmospheric pressure across much of the continent, effectively capping warm air at lower altitudes. Sinking atmospheric air undergoes compression and additional heating, enabling abnormally high temperatures to develop.
