EF1 tornado in Woodbury County, Iowa

A tornado touched down near the intersection of Glen Ellen Rd. and County Home Rd. and moved northeast for less than one mile before damaging several buildings along Old Highway 141. The tornado continued northeast for a couple minutes across open fields before damaging roof panels on an outbuilding along the south side of 180th Street. Across the road, a garage attached to a single family home was destroyed and several large branches snapped. The tornado then crossed Charles Ave. north of 180th St. before lifting in the adjacent field to the east. The tornado was rated EF1 with an estimated peak wind of 90 mph and an average path width was 75 yards.

An approaching mid-level disturbance broke a weak cap and allowed storms to erupt during the afternoon along a slow moving frontal boundary. These storms rapidly organized into short bowing segments and then became highly linear across northwest Iowa and southwest Minnesota during the evening. Initial supercell storms produced large hail with as much as 2000-3000 J/kg MLCAPE, but DCAPE of around 750-1000 J/kg allowed for the development of organized cold pools and an increasing wind threat. Several brief and highly visible tornadic spin-ups developed along the line of storms by late afternoon and evening across far eastern South Dakota, northwest Iowa and southwest Minnesota.

In addition, repeated thunderstorms brought as much as 2-4 inches of rain in a short period of time to portions of Plymouth and southern Sioux County in northwest Iowa. This same area had also received locally heavy rainfall during the previous days, resulting in spotty flooding of already saturated locations.