A powerful shift in the polar vortex is sending repeated waves of bitter Arctic air into the central and eastern United States, driving temperatures down toward – and in some places below – long-standing record lows from Iowa to Maine.
Forecasters say this is just the beginning: two additional rounds of severe cold are expected to impact tens of millions of people over the next two weeks.
“The week will end with some of the coldest air of the season so far, as a front advances from the Midwest into the Northeast and mid-Atlantic,” said Renee Duff, AccuWeather senior meteorologist.
According to Duff, a disruption and southward push of the polar vortex is allowing frigid Arctic air to spill into the central and eastern U.S. “A second cold outbreak is in the forecast next week, and a third round of frigid air is likely during the middle of the month,” she said.
How cold will it get?
The first punch of this pattern already delivered brutally cold temperatures to parts of the Midwest and Northeast on Friday. Record lows were set or tied in several locations, including 0 degrees in Springfield, Illinois; 3 degrees in Kalamazoo, Michigan; minus 4 degrees in Plattsburgh, New York; and 6 degrees in Scranton, Pennsylvania.
In Iowa on Thursday, more than a dozen cities set new record lows. In Waterloo, the temperature fell to minus 15 degrees, shattering the previous record of minus 7 degrees set in 1991.
More records may fall in the coming days. “Some subzero overnight lows are likely across portions of the Dakotas and into Minnesota, especially by Sunday morning in the wake of the next arctic front,” the National Weather Service (NWS) said.
For the next couple of days, the NWS is calling for roughly the following daytime highs:
- Midwest: teens to 20s
- New England: 20s and 30s
- Central/Southern Plains east to the mid-Atlantic: 30s and 40s
- Texas and the Southeast: 40s and 50s
Snow and travel impacts
Along with the bitter cold, snow will add to weather-related hazards.
“Snow will once again set the holiday mood this weekend for approximately 60 million people from the Plains to the Midwest, accumulating several inches and causing slippery travel,” AccuWeather meteorologists said.
A band of accumulating snow, generally in the 1- to 3-inch range, is expected to stretch from Montana to Iowa during the day on Saturday, then shift eastward across parts of the Great Lakes and Ohio Valley from Saturday night into Sunday, according to AccuWeather.
What is the polar vortex?
The “polar” in polar vortex refers to a large region of low pressure and cold air that typically sits over Earth’s north and south poles. The “vortex” describes the counterclockwise circulation of air that helps confine this cold air near the poles.
During winter in the Northern Hemisphere, the polar vortex can weaken or become distorted. When that happens, chunks of very cold air can move southward along the jet stream, bringing Arctic conditions to parts of the United States, the NWS explains.
Staying safe if you lose power
With prolonged cold snaps, the risk of power outages rises, making preparation critical.
AccuWeather urges people to finish winterizing their homes and water lines and to have their heating systems inspected and fuel (such as heating oil or propane) ordered as soon as possible.
If you lose power and your primary heat source:
- Only use generators, grills and camp stoves outside and away from windows to prevent carbon monoxide poisoning.
- Never use an oven or stovetop to heat your home; this greatly increases the risk of carbon monoxide buildup and house fires.
- Use battery-powered lanterns or flashlights instead of candles to reduce fire risk.
- Close off rooms you don’t need to help conserve heat.
- Use fireplaces and space heaters with extreme care. Keep anything that can burn at least 3 feet away from any heat source.
Staying safe outdoors in extreme cold
If you must go outside during dangerous cold, the American Red Cross recommends covering as much exposed skin as possible to reduce the risk of frostbite.
- Wear layers of loose-fitting, warm clothing and a hat.
- Choose mittens that fit snugly at the wrists instead of gloves, as they tend to keep hands warmer.
- Use a ski mask or scarf to cover your face.
- Wear water-resistant boots, if available, to help keep your feet dry and warm.
With multiple rounds of Arctic air in the forecast, experts say preparation now – both at home and when traveling – will be key to staying safe through this extended cold spell.
