As of moments ago, the NWS in Huntsville upgraded portions of North Alabama to an extreme cold warning. This extreme cold warning is in effect for the following counties: Cullman, Marshall, Dekalb, and Jackson. This is in effect from 9pm tonight until 12pm Monday. Within the extreme cold warning, wind chills could drop below 0 in some areas.
In addition, the remaining north Alabama counties not included in the extreme cold warning remain under a cold weather advisory, which is being bumped up to start at 9pm as well.
