An arctic air mass will channel temperatures 20-30 degrees below already historically cold January averages. The South braced for a rare winter storm.

An Extreme Cold Warning is in effect for the northern South Plains, with a Cold Weather Advisory elsewhere from 6 PM this evening until noon on Tuesday. If you must be outside, dress in layers and cover exposed skin to avoid frost bite. Tuesday will remain cold especially in the morning thanks to the wind chill.

More than 170 million people across the United States, from the Mexican border to the Canadian border are under cold weather alerts ahead of a crippling winter storm expected to sweep through the south from Texas to Georgia,