Prolonged Chill Tightens Hold on the Great White North as United States Experiences Warmest Christmas in History.
An intense cold spell has seized an intense and prolonged cold spell, with thermometers lingering from 20 to 40 degrees below zero for weeks. On Tuesday, Braeburn in the Yukon recorded -55.7C, representing its most frigid December day since 1975.
Consecutive Nights of Extreme Cold
In addition, the locales of Mayo and Dawson suffered through over two straight weeks of nights colder than minus 40 degrees, with the temperature in Mayo bottoming out at -50.4 degrees Celsius on Monday. Whitehorse similarly reported a series of ten nights when temperatures dropped below -30C.
The deep freeze spread farther south during the holiday season. Christmas night saw Edmonton's temperatures plummet below minus 28C.
December 26th was anticipated to usher in minimum temperatures of at least minus 20C through a wide swath, encompassing cities from Edmonton to Quebec.
Forecast to Persist into the New Year
The severe cold is forecast to persist through the start of January. Authorities have cautioned about potential power failures in the Yukon soon, as the system endures record-high pressure from peak power usage levels.
The lengthy cold snap originates from a stationary polar vortex over Canada for much of December, enabling a surge of icy Arctic winds to descend. In the coming week, forecasts indicate this cold air will pull back northward slowly, permitting warmer Pacific winds to flow over the US and into parts of southern Canada.
Pronounced Disparity with US Warmth
Conversely, sections of America recorded the hottest December 25th in their history as temperatures soared about 15-30C above the seasonal average. In many areas, conditions felt more typical of April or May rather than the end of December.
Multiple states established new Christmas temperature highs. Oklahoma City, Oklahoma, reached 25 degrees Celsius on Christmas, topping the prior high mark of 22 degrees established over forty years ago. Metropolitan areas such as Austin, Dallas, and Charlotte also logged readings above 25 degrees Celsius.
High-Pressure System Sustains High Temperatures
Warmer-than-normal conditions are forecast to last on December 26th and into the weekend, with unseasonable heat forecast to sweep through the American Southeast soon.
This heat is being driven by a strong upper-level ridge stretching from the southwestern deserts northward and eastward, establishing a classic heat-dome pattern. This pattern establishes a broad area of high pressure across much of the continent, which holds warm air close to the ground. Sinking atmospheric air undergoes compression and additional heating, allowing unusually warm temperatures to build.
