December 2021 North American storm complex and derecho
On Monday, December 13 just before 2:30 am Central Standard Time (0830 UTC), forecasters stated a level 1/5 marginal risk for severe weather between 60 and 78 hours from there. The original severe likelihood was focused on areas from eastern Nebraska, across Iowa and south central Minnesota. Two days following that, just before midnight on December 14 (0600 UTC December 15), the level was upgraded towards moderate in north central and western Iowa. The same level of probability extended into southeastern Minnesota and west-central Wisconsin near La Crosse, Winona and nearby Rochester. Slight or enhanced chances involved other areas of the same states. Included in the slight or enhanced risk area were Eau Claire, the Minneapolis–Saint Paul Metropolitan Area and the Cedar Rapids–Iowa City metropolitan regions of eastern Iowa. That was the first moderate risk ever called across Iowa, Wisconsin and Minnesota in December of any year.