Another Polar Vortex Is Coming To The East Coast

After a relatively mild weekend that had many in the Northeast thinking that Spring had finally sprung, the dreaded polar vortex is expected to return this week, bringing colder than normal temperatures to the central and eastern United States through the start of the work week, the National Weather Service warned on Monday.

"A cold mass of arctic air will bring temperatures that are 10 to 30 degrees below normal across the northern third of the U.S. on Monday," the weather service said.

The upper Midwest will be hardest hit, with temperatures of 20 to 40 degrees below normal for this time of year.

By Tuesday night, many eastern states should be feeling the cold, which the Climate Prediction Center says expected to last into the first week of March, according to USA Today.

The polar vortex first made headlines in early January when it brought tundra-like temperatures to huge parts of the nation. This weather phenomenon is caused when a huge mass of very cold air - normally trapped over the North Pole by spinning winds - splits apart and and plunges toward the equator, bringing a blast of freezing air down through northern Canada and into the the United States.