EF2 tornado in Jo Daviess County, Illinois

A tornado developed northwest of Stockton in Jo Daviess County, and moved E/SE along an intermittent 15 mile path, before lifting near Lena in Stephenson County. In Jo Daviess County, the tornado snapped a wooden power pole near the base, snapped tree trunks, and impacted a farmstead, with damage to an outbuilding and grain elevator supports. The most significant damage in Jo Daviess County was rated EF-2, with maximum winds around 115 mph. The tornado crossed into Stephenson County about a third of a mile south of W. Gerbick Road, around 18:01 CST. A public photo showed the tornado near Lena before it dissipated around 18:09 CST. There was no observable damage in Stephenson County.

Thunderstorms rapidly developed over northern Iowa during the afternoon and organized into a powerful line of wind producing storms that surged through the Quad Cities and into northern and central Illinois through the evening hours. These storms brought widespread damaging winds up to 100 mph for many locations, extending across eastern Iowa, much of Illinois, and into Indiana. The Storm Prediction Center has classified this event as a Derecho which by definition is a swath of wind damage at least 400 miles long and at least 60 miles wide including several well-separated significant wind gusts over 75 mph. Corridors of significant wind damage occurred along Highway 20. 10 tornadoes also occurred with these storms in the NWS Quad Cities service area.

In addition to the wind, very heavy rainfall fell in a short amount of time with many locations seeing over an inch. The highest totals fell in McDonough and Warren counties in Illinois where amounts between 2 and 3 inches fell.