A polar-vortex event is set to hit the northeastern US this weekend, bringing snow and potentially record-breaking springtime cold

Two women take photos of a cherry blossom tree in the springtime. Getty Images/Dan Kitwood
  • Parts of the northeastern US might see temperatures in the 30s and 40s on Saturday and Sunday. Some New England states could get snow.
  • The National Weather Service warned Americans to expect “widespread record and near record low” temperatures.
  • According to forecasters, this late-spring chill will come as the polar vortex – a mass of low-pressure cold air that circulates in the stratosphere above the Arctic – spills southward.
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Although the northern hemisphere is already more than halfway through the spring, some northeastern US states could see snow this weekend.

Parts of Pennsylvania, New York, Vermont, New Hampshire, and Maine should expect some snowfall late Friday and Saturday,Accuweather reported. That will coincide with a band of colder-than-usual weather set to hit the Great Lakes region and most of New England.

Temperatures are expected to be about 15 or more degrees Fahrenheit below average, according to the Washington Post, and hover in the 30s and low 40s.

According to Accuweather forecasts, temperatures in Fairbanks, Alaska, are expected to be higher than those in New York City, Philadelphia, and Atlanta during the weekend.

Polar vortex forecast
US temperature forecast through 5 p.m. Eastern Time on May 9, 2020. National Weather Service/NOAA

Even states as far south as Georgia and the Carolinas could see frost. The National Weather Service (NWS) warned that “over some areas, this cold surge would lead to a late frost/freeze where the growing season has already started.”

“It’s like a late-spring version of the polar vortex,” Paul Pastelok, an AccuWeather forecaster, said.

“If this same pattern was going on during January and February,” he added, “we would be in a deep freeze with frequent snowstorms in the eastern United States.”

The last time the US experienced a polar-vortex event – in January and February 2019 – temperatures in some parts of the Midwest plummeted to minus 66 degrees Fahrenheit with wind chill, and 84 million Americans experienced subzero temperatures.

Polar vortex
Steam rises on the surface of Lake Michigan, January 30, 2019, in Chicago. Kiichiro Sato/AP

Fortunately, this impending polar-vortex event won’t be nearly as severe.

How the polar vortex works

The term polar vortex describes the mass of low-pressure cold air that circulates in the stratosphere above the Arctic and Antarctic. Sometimes the circulation of the polar vortex weakens, causing surges of frigid air to splinter off and drift south. The freezing air is carried by the jet stream, a current of wind that extends around the hemisphere and divides the air masses in the polar region from those farther south.

North America, Europe, and Asia can all experience polar-vortex events, which bring temperatures that are simply colder than historical averages to areas south of the Arctic.

According to the NWS, the band of cold air dropping southward into the US on Saturday and Sunday “will lead to widespread record and near record lows” for this time of the year.

Polar Vortex Explainer
How the jet stream impacts the polar vortex. BI Graphics/NOAA

A polar air mass has always been present, but scientists first dubbed it the “polar vortex” in January 2014, when a cold snap hit a majority of the continental US.

The severe polar vortex that engulfed the US in early 2019 killed dozens and sent hundreds of people to the hospital with frostbite and hypothermia.