A major meteorological event is unfolding across the United States, with the National Weather Service (NWS) issuing winter weather warnings for a staggering 30 states. The cause is a destabilised polar vortex, which is funelling bone-chilling Arctic air southwards from Canada and Greenland, promising a week of record-breaking cold and disruptive snowfall.
Widespread Warnings and Forecast Extremes
The NWS has activated winter weather advisories and storm watches across the Midwest and Northeast. Meteorologists predict temperatures will plummet far below freezing, with the heaviest snow arriving on Monday night. Parts of Ohio, eastern Pennsylvania, upstate New York, and most of New England could see up to six inches of accumulation by Tuesday.
The cold is set to be exceptionally severe. Large areas of the Midwest, including Iowa, Illinois, Indiana, and Michigan, may see temperatures drop into single digits (Fahrenheit) today and Tuesday. Meanwhile, the Dakotas, Montana, Wyoming, Wisconsin, and Minnesota are bracing for their coldest days of the year on Monday, with some areas potentially falling below zero degrees Fahrenheit overnight.
Understanding the Polar Vortex Breakdown
This frigid onslaught is a direct result of a weakening in the Earth's polar vortex. Normally, this spinning pool of cold air is contained high above the North Pole by strong winds. However, disturbances in the lower atmosphere have sent ripples of warmer air upward, knocking the vortex off balance and allowing the icy air to spill south over the US.
The consequences are already being felt. Over the weekend, a 45-car pileup on Interstate 70 near Terre Haute, Indiana was attributed to the wintry conditions. Further travel disruption, both on the ground and in the air, is anticipated, with some schools likely to close temporarily.
Ice, Rain, and a Long-Lasting Chill
The hazards extend beyond snow. Ice warnings are in effect for Monday night and Tuesday morning in parts of Maryland, Virginia, West Virginia, and North Carolina, raising concerns over treacherous roads. Meanwhile, southern states from coastal Virginia to northern Florida are expected to face significant rainfall.
AccuWeather warns that parts of at least 20 states may see temperatures up to 20 degrees below historical averages for early December. The cold is projected to reach as far south as Oklahoma, Arkansas, Missouri, and Tennessee by Wednesday and Thursday. In Iowa, forecasts suggest Thursday could see temperatures below -10°F, which would smash decades-old records.
Looking ahead, climatologist Judah Cohen from MIT told USA Today that this early December cold may be just "the appetizer," with his models forecasting "the most expansive region of most likely extreme cold on Earth" stretching from the Canadian Plains to the US East Coast in the third week of December. The nation is advised to prepare for a prolonged and severe winter weather episode.
