CHICAGO (AP) - A whirlpool of frigid, dense air known as a "polar vortex" is descending into much of the U.S., pummeling parts of the country with a dangerous cold that could break decades-old records.
For a big chunk of the Midwest, the subzero temperatures are following heavy snow and high winds. Officials have closed schools in cities including Chicago, St. Louis and Milwaukee and warned residents to stay indoors and avoid the frigid cold altogether.
Actual temps are 20 to 30 below zero with wind chills dropping into the minus 50s and 60s. There is a wind chill warning in effect until Tuesday morning. School has been called off in all of Eastern South Dakota and the Governor of Minnesota ordered all schools closed in that state.
It hasn't been this cold for almost two decades in many parts of the country.