Seven million people were under winter storm warnings from Montana to Michigan early Monday ahead of a blast of freezing temperatures that will reach the East Coast later this week.
Six inches or more of snow is possible in a wide swath from the Dakotas to Minnesota and northern Wisconsin and Michigan. Forecasters say the snow will taper off in the Rockies and Plains by Monday evening but will continue to fall in Minnesota, Wisconsin and Michigan through Tuesday.
In Minneapolis, which could get a foot or more of wind-whipped snow, residents braced for a hellish evening commute and rushed out to buy shovels. "I've seen a lady with five today," Jazz Crosby, a cashier at Kendall's Ace Hardware, told NBC station KARE.
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A cold surge will sweep in behind the snow, with two-thirds of the country seeing below average temperatures by Friday, Weather.com reported. Montana took the plunge on Sunday, with the mercury sliding from 49 degrees to 27 degrees in just one hour.
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Rapid City, South Dakota, won't get out of the 20s on Monday, and a few places could set records lows. But it's the duration of the cold air that's unusual this early in the season; Minneapolis could stay below 32 degrees for seven days straight. The weather is part of a system being pushed in by the remnants of Typhoon Nuri that hit Alaska's Aleutian Islands with hurricane-strength winds over the weekend.
--The Associated Press contributed to this report.