One weather map tells the story.
Check out the National Weather Service's map of the Lower 48 for Monday night. If you need to know just how much of the nation's going to be freezing (or well below!), it offers a bone-chilling picture. Anywhere in the blue-to-purple shades is going to be cold — and that's before accounting for wind chills.
What is the Weather Service forecasting?
"Cold temperatures and gusty winds associated with an arctic airmass will continue dangerously cold wind chills as far south as Brownsville, Texas and central Florida. This arctic airmass will affect the eastern two-thirds of the country on Monday as a sharp cold front moves towards the East Coast. The cold temperatures will remain in place through mid-week before a warming trend begins."
The Weather Channel says this is the "coldest Arctic outbreak ... since the 1990s."
With wind chills factored in, the network adds, parts of Minnesota, the Dakotas and adjacent states are going to feel like its minus-40 degrees (or even less) in the next day or so.
The culprit behind this frigid blast is the "polar vortex," a low pressure system that's usually whirling around the North Pole but has weakened and come south. As The Washington Post's Capital Weather Gang says, the polar vortex is "diving into the Lower 48."
The BBC adds that "the vortex has been very strong, with the cold air locked in to Arctic Canada for a long time. Stuck in one place, the air has got colder and colder. Cold air is dense so once it is released it travels a long way and that is why it is penetrating so far southwards, John Hammond from the BBC Weather Centre says."
But the good news, The Weather Channel adds, is that:
"By Wednesday, subzero high temperatures will be virtually gone from the Lower 48 States. Thursday, highs in the 20s or 30s in much of the Great Lakes and Northeast will seem downright balmy compared to earlier in the week."
Headlines and links also help tell the story:
— "Deep Freeze Descends." (Minnesota Public Radio)
— "Wisconsinites Brave Deep Freeze." (Wisconsin Public Radio)
— "Bundle Up, Chicago." (WBEZ)
— "Extreme Cold Begins To Set In." (Cleveland's The Plain Dealer)
— "Bitterly Cold, Windy Conditions Expected For Area." (Rochester, N.Y., Democrat & Chronicle)
— " 'Polar Vortex' Puts Midwest In Deep Freeze; Heads To D.C." (The Washington Post)
— "Dallas Faces Temps In Teens, Wind Chill Near Zero This Morning." (The Dallas Morning News)
— "Temperatures To Plummet As Cold Snap Sets In Monday Afternoon In Orlando." (The Orlando Sentinel)