It’s cold now, but another punch of arctic air will take it to another level. Due to recent winter storms, more than 200 million people will wake up to freezing temperatures as the coldest air of the season sweeps across the Plains, Midwest, Great Lakes and Northeast. This extensive dive puts dozens of daily records in play.
After lots of snow last week, the Midwest is now bracing for some of the coldest temperatures of the season.
Bitter cold from Canada will move into the Northern Plains and upper Midwest on Wednesday. High temperatures will be 15 to 25 degrees below normal and parts of the Dakotas will struggle to reach 10 degrees. More than a dozen cities in the upper Midwest could set new record cold daily highs.
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Thursday morning will be the coldest as actual air temperatures are forecast to drop into the double digits below zero in southern Iowa and Nebraska. Wind chills of -10 to -25 will be common.
Des Moines and Cedar Rapids, Iowa, are each set to break daily low temperature records Thursday, dropping to -11 degrees and -7 degrees, respectively. Cedar Rapids may only warm to single digits above zero Thursday afternoon, which would set a new record for coldest high temperature for the day.
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Afternoon temperatures in much of the Midwest will be stuck in the teens — 20 to 30 degrees below normal for early December.
Records could also fall from Illinois to the East Coast on Friday morning. Chicago could drop its daily minimum temperature by 4 degrees below the record while Indianapolis could reach a record 8 degrees – last set in 1886. Low temperatures will be in the teens across Pennsylvania, breaking daily records in many cities.
Friday morning will be New York City’s coldest day since early March, with temperatures in the low 20s. Records could fall for the city’s JFK and LaGuardia airports. Cold wind will sting.
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Blame the polar vortex
The winter storms that hit the U.S. this week — and those forecast for the next two weeks — may be linked in large part to the displacement of the polar vortex that began in late November, researchers told CNN.
The polar vortex is a circular flow of intense air in the Arctic that can trap cold air in that region. Recently, however, it has weakened and moved south toward the mid-latitudes, blowing cold, arctic air into heavily populated areas.
That could create tornado conditions, said Andrea Lopez Lang, a meteorologist at the University of Wisconsin-Madison, as cold air from up north collides with relatively warm air.
And a weak polar vortex also means a wavy jet stream. These are air currents that flow west-to-east in the Northern Hemisphere. A wavy jet stream can give people whiplash, said MIT meteorologist Judah Cohen.
For the remainder of December, we can expect frequent oscillations between mild-to-average conditions and cooler temperatures as storms move through.
However, López Lang cautioned that this polar vortex phenomenon is not the only factor behind those upcoming temperature fluctuations. “It’s definitely contributing, but it’s not the whole story,” she said.
Is this the end of the cold snap? Amy Butler, NOAA’s research meteorologist, warned of another cold snap by mid-December. “This polar vortex appears to spread further into North America in about 7-10 days,” he noted.
We’re still about three weeks away from the official start of winter, but Mother Nature is off to a pretty head start.
CNN meteorologists Mary Gilbert and Taylor Ward contributed to this report.
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