An area of severe thunderstorms formed during the later afternoon hours of Monday, and continued into the early evening. The storms mainly impacted northeast Iowa into southwest Wisconsin by producing numerous reports of large hail, damaging wind, and a short-lived tornado.
The hardest hit areas were in Winneshiek County, Iowa where high winds damaged buildings and trees. There were lots of reports of barns damaged, siding tore off houses, windows broken, and rooftop damage around the region. Wind gusts of 60-80 mph were fairly common and hail reached up to 2″ in diameter.
A NWS Storm Survey Team found a broken damage path from an EF-0 tornado near Lake Meyer (southwest of Calmar) in southern Winneshiek County. The damage was mainly seen in trees along the path.
Overnight, storms redeveloped near the Interstate 90 corridor around 10 p.m. and remained stationary near the Mississippi River for several hours. Besides keeping many people awake, over 4 inches of rain fell in some areas in Wabasha and Winona counties. Some flooding was reported.