Deep Freeze Grips Canada 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 between -20C and -40C for an extended duration. On Tuesday, Braeburn in the Yukon recorded -55.7C, its coldest December temperature in nearly five decades.
Consecutive Nights of Extreme Cold
Meanwhile, Mayo and Dawson endured 16 consecutive nights colder than minus 40 degrees, with Mayo plunging to -50.4C at the start of the week. The capital, Whitehorse, likewise saw 10 nights when readings fell to minus 30 degrees or lower.
The bitter chill extended its reach south over the festive period. Christmas night saw Edmonton's temperatures plummet below minus 28C.
December 26th was anticipated to usher in readings no higher than -20 Celsius in numerous areas, encompassing cities from Edmonton to Quebec.
Forecast to Persist into the New Year
This harsh winter weather is expected to continue through the start of January. Authorities have cautioned about potential power failures in the Yukon soon, as the territory’s power grid comes under strain from peak power usage levels.
The lengthy cold snap originates from the polar vortex remaining anchored above Canadian territory through December, which funnels frigid northern air southward. In the coming week, forecasts indicate this cold air will pull back northward gradually, enabling milder Pacific air to move across the United States and penetrate southern Canadian regions.
Pronounced Disparity with US Warmth
Conversely, sections of America recorded their warmest Christmas Day on record as the mercury climbed roughly 15 to 30 degrees above typical averages. In many areas, conditions felt more typical of April or May instead of the heart of winter.
Several states set Christmas Day temperature records. The capital of Oklahoma soared to 25C on Christmas Day, exceeding the old record of 22C from 1982. Metropolitan areas such as Austin, Dallas, and Charlotte were also among those that recorded temperatures above 25C.
Heat-Dome Effect Sustains High Temperatures
Warmer-than-normal conditions are forecast to last on December 26th and into the weekend, with atypical high temperatures expected to spread into the south-eastern states later in the week.
The unseasonable temperatures are powered by a strong upper-level ridge extending from the desert south-west towards the north and east, establishing a classic heat-dome pattern. This setup creates an extensive zone of high atmospheric pressure blanketing a significant part of the landmass, which holds warm air close to the ground. Descending air compresses and adiabatically warms, allowing unusually warm temperatures to build.
