Arctic temperatures, snow and flooding sweep across the U.S.

Wintry weather is sweeping across parts of the United States this weekend, bringing with it brutally low temperatures

Wintry weather is sweeping across parts of the United States this weekend, bringing with it brutally low temperatures.

Nearly 49 million people from the northern Plains through the Southeast are under cold weather alerts. Affected cities include Minneapolis, Chicago, St. Louis, Nashville, Memphis, Atlanta, New Orleans, Jacksonville, Raleigh, Huntsville and Myrtle Beach.

Dangerously cold wind chills are expected to hit these areas, with the National Weather Service issuing some alerts that run into Monday morning.

People walk in cold weather along the Brooklyn Bridge in New York City on Monday.Spencer Platt / Getty ImagesThe most extreme temperatures will hit the northern Plains and Midwest on Saturday night, where overnight temperatures could dip as low as minus 25 degrees.

Wind chills will make it feel like minus 30 to minus 35 degrees in the Dakotas, Minnesota and Wisconsin.