Significant severe storms on April 14-15 produced baseball-sized hail, 88 mph wind gusts at Dubuque Airport and multiple tornadoes along the U.S. Highway 20 corridor supercell, plus additional large hail and a tornado near Onslow, Iowa. Storms south of Interstate 80 also contributed to widespread severe impacts.
Source: National Weather Service. Original: https://www.weather.gov/dvn/summary_041726