* WHAT...For the Extreme Cold Warning, dangerously cold wind chills as low as 50 below. For the Cold Weather Advisory, very cold wind chills as low as 40 below expected. * WHERE...Portions of north central and northwest Minnesota and northeast and southeast North Dakota. * WHEN...For the Extreme Cold Warning, until noon CST today. For the Cold Weather Advisory, from noon today to 9 AM CST Monday. * IMPACTS...The dangerously cold wind chills as low as 50 below zero could cause frostbite on exposed skin in as little as 5 minutes.