Arctic Blast Tightens Hold on the Great White North as United States Experiences Warmest Christmas Ever.
A prolonged deep freeze has enveloped a bitter and extended period of frigid weather, with readings persisting from 20 to 40 degrees below zero for weeks. A reading of -55.7 Celsius was logged in Braeburn, Yukon, on Tuesday, marking its chilliest December reading since 1975.
Enduring Chill Below -40C
Meanwhile, Mayo and Dawson endured over two straight weeks of nights below -40C, with the temperature in Mayo bottoming out at -50.4 degrees Celsius on Monday. Whitehorse similarly reported 10 nights when temperatures dropped below -30C.
The bitter chill extended its reach south during the holiday season. On Christmas Day, overnight temperatures in Edmonton fell below -28C.
December 26th was anticipated to usher in readings no higher than -20 Celsius through a wide swath, encompassing cities from Edmonton to Quebec.
Forecast to Persist into the New Year
This harsh winter weather is expected to continue into the new year. Officials have warned that the Yukon could face electricity outages soon, as the territory’s power grid comes under strain from historically high electricity consumption.
This extended freeze is the result of the polar vortex remaining anchored 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 America and reach into portions of southern Canada.
Dramatic Difference with US Warmth
Meanwhile, in a dramatic contrast, areas of the United States saw the hottest December 25th in their history as readings skyrocketed 15 to 30 degrees Celsius above normal. For numerous locations, the weather resembled a spring day in April or May instead of the heart of winter.
Several states set Christmas Day temperature records. In Oklahoma, Oklahoma City hit 25C on Tuesday, exceeding the old record of 22C from 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 on December 26th and into the weekend, with abnormal warmth projected to move across the southeastern US in the coming days.
This heat is being driven by a powerful high-altitude 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, which holds warm air close to the ground. Descending air compresses and adiabatically warms, allowing unusually warm temperatures to build.
