Prolonged Chill Tightens Hold on the Great White North as United States Experiences Most Unseasonably Mild Christmas in History.
A prolonged deep freeze has enveloped a bitter and extended period of frigid weather, with temperatures hovering from 20 to 40 degrees below zero for weeks. This week, the Yukon community of Braeburn saw the mercury drop to -55.7C, representing its most frigid December day in nearly five decades.
Enduring Chill in the Deep Minus Forties
In addition, the locales of Mayo and Dawson suffered through 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 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 lows of at least -20C through a wide swath, including Edmonton, Montreal, Ottawa and Quebec.
Forecast to Persist For Days to Come
The severe cold is forecast to persist for the foreseeable future. Authorities have cautioned about potential power failures in the Yukon soon, as its energy infrastructure faces unprecedented demand from record-high energy demand.
This extended freeze is the result of the Arctic vortex settling across the northern part of the continent this month, allowing bitter Arctic air to spill south. In the coming week, forecasts indicate this cold air will pull back northward gradually, enabling milder Pacific air to move across the US and into parts of southern Canada.
Stark Contrast to American Heat
Conversely, sections of America recorded historically high temperatures for Christmas as temperatures soared about 15-30C above the seasonal average. Across wide regions, the atmosphere was more akin to late spring instead of the heart of winter.
Multiple states established new Christmas temperature highs. In Oklahoma, Oklahoma City hit 25C on Tuesday, surpassing the previous peak of 22C set in 1982. Urban centers like Austin, Dallas, and Charlotte, North Carolina also logged readings above 25 degrees Celsius.
High-Pressure System Fuels Warmth
Above-average warmth is expected to continue for the remainder of the week and beyond, with atypical high temperatures expected to spread across the southeastern US in the coming days.
The unseasonable temperatures are powered by a robust atmospheric ridge stretching from the southwestern deserts northward and eastward, creating a heat-dome effect. Such a configuration results in a widespread high-pressure system blanketing a significant part of the landmass, effectively capping warm air at lower altitudes. Descending air compresses and adiabatically warms, fostering the buildup of exceptional warmth.
