Deep Freeze Tightens Hold on Canada as United States Experiences Most Unseasonably Mild Christmas in History.
Northern Canada has been gripped by an intense and prolonged cold spell, 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, marking its chilliest December reading in half a century.
Prolonged Freeze Below -40C
In addition, the locales of Mayo and Dawson suffered through over two straight weeks of nights colder than minus 40 degrees, with Mayo experiencing a low of -50.4C at the start of the week. The capital, Whitehorse, likewise saw a series of ten nights when temperatures dropped below -30C.
The bitter chill extended its reach south through Christmas week. In Edmonton, the Christmas overnight low dipped under -28 degrees Celsius.
December 26th was anticipated to usher in lows of at least -20C across many regions, from Edmonton in the west to Quebec in the east.
Forecast to Persist For Days to Come
This harsh winter weather is expected to continue through the start of January. Officials have warned that the Yukon could face electricity outages in the coming days, as the territory’s power grid comes under strain from historically high electricity consumption.
The prolonged chill has been caused by a stationary polar vortex above Canadian territory through December, enabling a surge of icy Arctic winds to descend. The frigid dome is projected to gradually withdraw north slowly, permitting warmer Pacific winds to flow over America and reach into portions of southern Canada.
Pronounced Disparity with US Warmth
In stark contrast, parts of the US experienced their warmest Christmas Day on record as readings skyrocketed 15 to 30 degrees Celsius above normal. For numerous locations, the weather resembled a spring day in April or May rather than the end of December.
Several states set Christmas Day temperature records. The capital of Oklahoma soared to 25C on Christmas Day, topping the prior high mark of 22 degrees established over forty years ago. Cities including Austin and Dallas, in Texas, and Charlotte, North Carolina also logged readings above 25 degrees Celsius.
High-Pressure System Fuels Warmth
Warmer-than-normal conditions are forecast to last through Boxing Day and the days ahead, with abnormal warmth projected to move across the southeastern US in the coming days.
The unseasonable temperatures are powered by a powerful high-altitude ridge reaching from the arid southwest across the continent, which generates a heat-dome phenomenon. Such a configuration results in a widespread high-pressure system over a large portion of North America, trapping warm air near the surface. Descending air compresses and adiabatically warms, enabling abnormally high temperatures to develop.
