Deep Freeze Tightens Hold on Canada as US Records Most Unseasonably Mild Christmas in History.
A prolonged deep freeze has enveloped an intense and prolonged cold spell, with temperatures hovering between -20C and -40C for an extended duration. A reading of -55.7 Celsius was logged in Braeburn, Yukon, on Tuesday, marking its chilliest December reading since 1975.
Enduring Chill in the Deep Minus Forties
Similarly, the communities of Mayo and Dawson experienced 16 consecutive nights below -40C, with Mayo experiencing a low of -50.4C on Monday. The capital, Whitehorse, likewise saw 10 nights when temperatures dropped below -30C.
The bitter chill extended its reach 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 across many regions, from Edmonton in the west to Quebec in the east.
Forecast to Persist into the New Year
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 lengthy cold snap originates from the polar vortex remaining anchored across the northern part of the continent this month, allowing bitter Arctic air to spill south. The frigid dome is projected to gradually withdraw north allowing more temperate air from the Pacific to sweep across the US and into parts of southern Canada.
Dramatic Difference with US Warmth
Conversely, sections of America recorded the hottest December 25th in their history as the mercury climbed roughly 15 to 30 degrees above typical averages. Across wide regions, the atmosphere was more akin to late spring instead of the heart of winter.
Several states set Christmas Day temperature records. Oklahoma City, Oklahoma, reached 25 degrees Celsius on Christmas, surpassing the previous peak of 22C set in 1982. Metropolitan areas such as Austin, Dallas, and Charlotte also logged readings above 25 degrees Celsius.
Atmospheric Ridge Sustains High Temperatures
Above-average warmth is expected to continue through Boxing Day and the days ahead, with abnormal warmth projected to move into the south-eastern states later in the week.
The warmth has been fuelled by a robust atmospheric ridge stretching from the southwestern deserts northward and eastward, creating a heat-dome effect. This setup creates an extensive zone of high atmospheric pressure over a large portion of North America, effectively capping warm air at lower altitudes. Descending air compresses and adiabatically warms, fostering the buildup of exceptional warmth.
