Polar Vortex to Plunge U.S. Back Into the Icebox

Temperatures are predicted to fall below normal for two-thirds of the contiguous U.S.

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Brace yourselves.

The polar vortex is once again expected to bring frigid temperatures back to much of the U.S. early next week.

Cities from New York to Chicago, Minneapolis, Detroit and Washington, D.C. – which had been basking in balmy above-freezing temperatures ranging from 40 to 55 degrees Wednesday and Thursday – were predicted to see temperatures plunge as low as 20 to 35 degrees below normal, the National Weather Service and the website Weather Underground reported.

The eastern two-thirds of the U.S., in fact, is expected to see below-average temperatures next week, after January averages already dipped “below normal” and “much below normal,” according to a monthly climate report by the National Oceanic and Atmospheric Administration made public Thursday.

Below-average temperatures are expected to sweep across two-thirds of the United States next week.

The projected cold spell comes from the northern polar vortex, a high-altitude flow of air that circles west to east above the North Pole. As global temperatures have risen, the difference in temperature between the Arctic and lower latitudes has shrunk, causing the vortex to become “wavier,” John Holdren, director of the White House Office of Science and Technology Policy, said in a YouTube video following similarly cold temperatures last month.

As more Americans have been forced to kick the heat up higher for longer, natural gas prices have soared, from about $4.30 at the start of December to a five-year high of $6.25 on Wednesday.