Much of the U.S. is about to get pretty cold again.
A huge dome of arctic air will send temperatures plummeting across parts of the Midwest and Northeast early this week in a deep freeze reminiscent of early January's "polar vortex."
Temperatures are expected to go well below zero in Minnesota by Tuesday, with some lows potentially reaching 20 below. Wisconsin, Michigan and upstate New York are expected to see some of the worst of the subzero temperatures through the earliest part of the week. Then the cold will move south.