The weather service describes, "Bitterly cold wind chills as low as 24 degrees below zero expected." "Bitterly cold wind chills as low as 24 below zero will cause frostbite on exposed skin in as little as 30 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. An extreme cold warning is issued when dangerously cold air temperatures or wind chill values are expected or occurring.