Prolonged Chill Tightens Hold on the Great White North as US Records Hottest Christmas Ever.
An intense cold spell has seized a bitter and extended period of frigid weather, with thermometers lingering from 20 to 40 degrees below zero for an extended duration. On Tuesday, Braeburn in the Yukon recorded -55.7C, representing its most frigid December day in nearly five decades.
Prolonged Freeze of Extreme Cold
Similarly, the communities of Mayo and Dawson experienced sixteen nights in a row dipping under the minus 40 Celsius threshold, with the temperature in Mayo bottoming out at -50.4 degrees Celsius at the start of the week. Whitehorse similarly reported 10 nights when the cold dipped under -30 Celsius.
The deep freeze spread farther south through Christmas week. Christmas night saw Edmonton's temperatures plummet below minus 28C.
Boxing Day was expected to bring readings no higher than -20 Celsius across many regions, from Edmonton in the west to Quebec in the east.
Expected to Continue For Days to Come
The severe cold is forecast to persist through the start of January. Authorities have cautioned about potential power failures in the Yukon over the next several days, as the system endures record-high pressure from record-high energy demand.
The prolonged chill has been caused by the Arctic vortex settling above Canadian territory through December, enabling a surge of icy Arctic winds to descend. In the coming week, forecasts indicate this cold air will pull back northward allowing more temperate air from the Pacific to sweep across America and reach into portions of southern Canada.
Pronounced Disparity Compared to Stateside Temperatures
In stark contrast, parts of the US experienced 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.
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 similarly saw thermometers rise past the 25C mark.
High-Pressure System Sustains High Temperatures
Warmer-than-normal conditions are forecast to last on December 26th and into the weekend, with unseasonable heat forecast to sweep into the south-eastern states later in the week.
The warmth has been fuelled by a strong upper-level ridge reaching from the arid southwest across the continent, which generates a heat-dome phenomenon. Such a configuration results in a widespread high-pressure system blanketing a significant part of the landmass, which holds warm air close to the ground. Descending air compresses and adiabatically warms, fostering the buildup of exceptional warmth.
