Extreme wind chills tonight. This is a warning that extreme wind chill conditions are imminent or occurring in these regions. Monitor weather conditions..Listen for updated statements. A pool of bitterly cold Arctic air has settled over Northern Saskatchewan with temperatures near minus 40. Tonight a brisk northwesterly flow will develop over the area producing extreme wind chill values in the minus fifties. The extreme wind chill values will continue on Saturday. At these extreme wind chill values frostbite on exposed skin may occur in less than 5 minutes.