Northern Canada has been gripped by a severe and lengthy Arctic outbreak, with readings persisting in the minus 20 to minus 40 Celsius range for an extended duration. A reading of -55.7 Celsius was logged in Braeburn, Yukon, on Tuesday, its coldest December temperature in nearly five decades.
Prolonged Freeze Below -40C
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 earlier this week. Whitehorse also recorded a series of ten nights when temperatures dropped below -30C.
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 minimum temperatures of at least minus 20C through a wide swath, including Edmonton, Montreal, Ottawa and Quebec.
Likely to Linger into the New Year
This harsh winter weather is expected to continue into the new year. There are warnings of possible electrical grid strain in Yukon territory soon, as the system endures record-high pressure from record-high energy demand.
The lengthy cold snap originates from the Arctic vortex settling over Canada for much of December, enabling a surge of icy Arctic winds to descend. The frigid dome is projected to gradually withdraw north allowing more temperate air from the Pacific to sweep across the United States and penetrate southern Canadian regions.
Stark Contrast Compared to Stateside Temperatures
In stark contrast, parts of the US experienced historically high temperatures for Christmas as the mercury climbed roughly 15 to 30 degrees above typical averages. In many areas, conditions felt more typical of April or May instead of the heart of winter.
Several states set Christmas Day temperature records. The capital of Oklahoma soared to 25C on Christmas Day, exceeding the old record of 22C from 1982. Cities including Austin and Dallas, in Texas, and Charlotte, North Carolina also logged readings above 25 degrees Celsius.
Heat-Dome Effect Fuels Warmth
Unseasonable heat is predicted to persist through Boxing Day and the days ahead, with unseasonable heat forecast to sweep across the southeastern US in the coming days.
This heat is being driven by a robust atmospheric ridge reaching from the arid southwest across the continent, establishing a classic heat-dome pattern. This setup creates an extensive zone of high atmospheric pressure over a large portion of North America, effectively capping warm air at lower altitudes. Sinking atmospheric air undergoes compression and additional heating, allowing unusually warm temperatures to build.
