Arctic air will move into the northern and central U.S. this weekend, bringing very cold air with dangerous wind chills.
Temperatures will be 20 to 40 degrees below average, with highs only reaching into the single digits with lows in the negative teens.
A winter storm strengthening across the northern Rockies and into the Plains and Midwest will bring heavy snow to some regions, while heavy rain will be the story for the Gulf Coast and Southeast.
Flash flooding will be the biggest threat for the next few days.