Its called the polar vortex. Which is the scientific term meteorologists use to explain the historic cold gripping a large section of the midwest right now. The rest of us just say its stunningly cold. The polar vortex is a counterclockwise rotation of dense arctic air thats built up over the north pole. And is then pushed south by the upper jetstream. It is producing wind chills that tomorrow night could have some sections of that region feeling like 60 below zero according to the National Weather service. Wisconsin will see its coldest weather in 18 years. In des moines, iowa, they have closed an ice skating rink because it was too cold. And in minnesota theyve already canceled School Statewide for monday. Thats where kate raddatz of our cbs station w. C. C. O. Picks up the story. Reporter high winds overnight made minusfive feel like minus29 as ice and snow closed down i29 in fargo. Frigid temperatures here in minnesota which can cause frostbite in less than five minutes led the gov