A potent shot of Arctic air starts settling in Monday as a massive dip in the jet stream pulls in frigid air across the entire eastern half of the country. Temperatures are set to drop as low as 20 degrees below average Tuesday and Wednesday with highs only reaching the teens, with lows in the single digits and even plunging below zero.

Temperatures will plummet by up to 40 degrees this weekend as an arctic blast spreads across much of the U.S., including the Deep South.

That's because a fresh batch of bitterly cold arctic air is set to arrive this weekend into early next week, possibly bringing the coldest lows of the winter so far in some cities as well as dangerously cold wind chills.