It's already cold but it's going to be getting even colder in a wide swath of the nation.
The Midwest, New England and even the South will be affected by a deep freeze, with potential record-low temperatures heightening fears of frostbite and hypothermia.
It hasn't been this cold for decades.
One meteorologist says, "If you're under 40 (years old), you've not seen this stuff before."
Storm Ready InformationSevere Weather WarningsSchool Closings & DelaysGet the NBC 25 News AppRadar & SkycamsRoad ConditionsFlight Information: Bishop, MBS, Detroit MetroSend Weather Photos to firstname.lastname@example.org
The frigid air will begin Sunday and extend into early next week. It will reach as far south as the Gulf Coast. Blame it on a "polar vortex," as one meteorologist calls it, a counterclockwise-rotating pool of cold, dense air.
The predictions are startling: 25 below zero in Fargo, N.D., minus 31 in International Falls, Minn., and 15 below in Indianapolis and Chicago. At those temperatures, exposed skin can get frostbitten in minutes and hypothermia can quickly set in as wind chills may reach 50, 60 or even 70 below zero.
Even wind chills of 25 below zero can do serious damage.