Significant severe storms on April 14-15 brought large hail up to baseball size, damaging winds up to 88 mph at Dubuque Airport, and multiple tornadoes along the U.S. Hwy 20 corridor and near Onslow, Iowa. Additional storms south of I-80 produced large hail and a photogenic tornado.
Source: National Weather Service. Original: https://www.weather.gov/dvn/summary_041426