Arctic Blast Envelops Canada as America Sees Most Unseasonably Mild 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 an extended duration. This week, the Yukon community of Braeburn saw the mercury drop to -55.7C, its coldest December temperature in nearly five decades.
Enduring Chill of Extreme Cold
Similarly, the communities of Mayo and Dawson experienced over two straight weeks of nights colder than minus 40 degrees, with Mayo experiencing a low of -50.4C earlier this week. Whitehorse also recorded 10 nights when the cold dipped under -30 Celsius.
The bitter chill extended its reach south during the holiday season. On Christmas Day, overnight temperatures in Edmonton fell below -28C.
The day after Christmas was forecast to deliver minimum temperatures of at least minus 20C across many regions, from Edmonton in the west to Quebec in the east.
Expected to Continue into the New Year
The severe cold is forecast to persist for the foreseeable future. There are warnings of possible electrical grid strain in Yukon territory over the next several days, as the system endures record-high pressure from historically high electricity consumption.
The lengthy cold snap originates from the polar vortex remaining anchored above Canadian territory through 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 the United States and penetrate southern Canadian regions.
Dramatic Difference Compared to Stateside Temperatures
Conversely, sections of America recorded historically high temperatures for Christmas as readings skyrocketed 15 to 30 degrees Celsius above normal. Across wide regions, the atmosphere was more akin to late spring than late December.
Multiple states established new Christmas temperature highs. In Oklahoma, Oklahoma City hit 25C on Tuesday, exceeding the old record of 22C from 1982. Cities including Austin and Dallas, in Texas, and Charlotte, North Carolina similarly saw thermometers rise past the 25C mark.
High-Pressure System Fuels Warmth
Above-average warmth is expected to continue on December 26th and into the weekend, with abnormal warmth projected to move into the south-eastern states later in the week.
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. Such a configuration results in a widespread high-pressure system over a large portion of North America, effectively capping warm air at lower altitudes. Sinking atmospheric air undergoes compression and additional heating, allowing unusually warm temperatures to build.
