On Thursday at 1:08 a.m. a cold weather advisory was issued by the National Weather Service valid from 7 p.m. until Friday 10 a.m. for Jefferson and Lewis counties. The weather service states, "Bitterly cold wind chills as low as 29 degrees below zero expected." "Bitterly cold wind chills as low as 29 below zero will cause frostbite on exposed skin in as little as 15 minutes. Understanding cold weather alertsCold weather advisory: Be Aware. A cold weather advisory is issued when seasonably cold air temperatures or wind chill values, but not extremely cold values, are expected or occurring.