Polar vortex to unleash frigid Arctic blast By Jeff Berardelli Ice storm lashes South ahead of snow and cold The polar vortex has become synonymous with winter's most brutal cold. For days, the weather system has been sitting and spinning right along the U.S.-Canada border, with temperatures as low as 43 degrees below zero in northern Minnesota. But now, there are signs it is about to surge south, bringing with it record-shattering cold air from the far reaches of Alaska and Northern Canada. By the weekend, temperatures in Kansas City and St. Louis will be below what's normal for Fairbanks, Alaska.