states, canada and around the world, i'm kim brunhuber. this is "cnn newsroom." more than 80 million americans are under windchill alerts through the weekend and beyond as a brutal arctic blast is making its way through the central u.s. and in some places frostbite could occur in less than ten minutes. cnn meteorologist lisa rafah breaks us down for us. >> the blizzard exits and the arctic air is diving south. windchill warnings in effect for the northern and central plains for windchills as cold as 45 degrees below zero. as that arctic air invades and spills south, this is some of the coldest air we've seen so far this season and it's coming right in time for the iowa caucus on monday. iowans waking up sunday morning to windchills as cold as 45 degrees below zero, frostbite, they are happening in ten minutes or less. by monday evening we're still looking at windchills as cold as 30 degrees below zero with frostbite times at 25 minutes or less. this would by far be the coldest