Arctic Blast Tightens Hold on the Great White North as US Records Hottest Christmas on Record.
A prolonged deep freeze has enveloped a bitter and extended period of frigid weather, with temperatures hovering in the minus 20 to minus 40 Celsius range for weeks. On Tuesday, Braeburn in the Yukon recorded -55.7C, representing its most frigid December day in nearly five decades.
Enduring Chill of Extreme Cold
In addition, the locales of Mayo and Dawson suffered through 16 consecutive nights below -40C, with Mayo plunging to -50.4C on Monday. The capital, Whitehorse, likewise saw ten separate nights when readings fell to minus 30 degrees or lower.
The bitter chill extended its reach south through Christmas week. Christmas night saw Edmonton's temperatures plummet below minus 28C.
The day after Christmas was forecast to deliver lows of at least -20C in numerous areas, including Edmonton, Montreal, Ottawa and Quebec.
Likely to Linger into the New Year
This harsh winter weather is expected to continue into the new year. Authorities have cautioned about potential power failures in the Yukon in the coming days, as the territory’s power grid comes under strain from peak power usage levels.
This extended freeze is the result of a stationary polar vortex above Canadian territory through December, which funnels frigid northern air southward. The frigid dome is projected to gradually withdraw north slowly, permitting warmer Pacific winds to flow over the US and into parts of southern Canada.
Stark Contrast with US Warmth
In stark contrast, parts of the US experienced their warmest Christmas Day on record 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.
Multiple states established new Christmas temperature highs. In Oklahoma, Oklahoma City hit 25C on Tuesday, exceeding the old record of 22C from 1982. Metropolitan areas such as Austin, Dallas, and Charlotte similarly saw thermometers rise past the 25C mark.
Atmospheric Ridge Drives the Heat
Warmer-than-normal conditions are forecast to last through Boxing Day and the days ahead, with unseasonable heat forecast to sweep through the American Southeast soon.
The warmth has been fuelled by a robust atmospheric ridge reaching from the arid southwest across the continent, 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, fostering the buildup of exceptional warmth.
