Prolonged Chill Grips the Great White North as US Records Most Unseasonably Mild Christmas in History.
An intense cold spell has seized a bitter and extended period of frigid weather, with readings persisting from 20 to 40 degrees below zero for multiple weeks. A reading of -55.7 Celsius was logged in Braeburn, Yukon, on Tuesday, its coldest December temperature in nearly five decades.
Prolonged Freeze in the Deep Minus Forties
In addition, the locales of Mayo and Dawson suffered through 16 consecutive nights dipping under the minus 40 Celsius threshold, with Mayo experiencing a low of -50.4C earlier this week. The capital, Whitehorse, likewise saw a series of ten 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.
The day after Christmas was forecast to deliver minimum temperatures of at least minus 20C in numerous areas, from Edmonton in the west to Quebec in the east.
Likely to Linger 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 in the coming days, as the system endures record-high pressure from peak power usage levels.
The prolonged chill has been caused by a stationary polar vortex across the northern part of the continent this month, enabling a surge of icy Arctic winds to descend. The frigid dome is projected to gradually withdraw north allowing more temperate air from the Pacific to sweep across the United States and penetrate southern Canadian regions.
Stark Contrast Compared to Stateside Temperatures
Conversely, sections of America recorded their warmest Christmas Day on record as the mercury climbed roughly 15 to 30 degrees above typical averages. For numerous locations, the weather resembled a spring day in April or May than late December.
A number of states broke historical records for December 25th warmth. Oklahoma City, Oklahoma, reached 25 degrees Celsius on Christmas, 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.
Atmospheric Ridge Fuels Warmth
Unseasonable heat is predicted to persist for the remainder of the week and beyond, with unseasonable heat forecast to sweep through the American Southeast soon.
This heat is being driven by a robust atmospheric ridge extending from the desert south-west towards the north and east, creating a heat-dome effect. This pattern establishes a broad area of high pressure across much of the continent, which holds warm air close to the ground. Descending air compresses and adiabatically warms, fostering the buildup of exceptional warmth.
