EF1 tornado in Buchanan County, Iowa

EF1 tornado with peak winds of 100-105 mph began east-southeast of Winthrop and tracked into Delaware County to just east-southeast of Masonville. A barn was completely destroyed at the beginning of its 4.3 mile long path. Additional damage to outbuildings and numerous trees was observed. The tornado also crossed U.S. Highway 20 just south of Masonville. The tornado did roll over a semi trailer.

Significant severe storms on the afternoon and evening of April 14th brought numerous reports of large hail, damaging wind, and multiple tornadoes. The U.S. Hwy 20 corridor saw a long lived supercell that producing large hail (up to baseball size), damaging wind (88 mph gust at the Dubuque Airport), and several tornadoes. Additional storms developed further south between I-80 and Hwy 20 that brought large hail and a photogenic tornado near Onslow, IA.

More storms quickly followed overnight and again on the next day, April 15th, bringing heavy rain, large hail, and isolated wind damage. Rainfall amounts over 1.5 were common north of I-80, with the highest totals over 3.5 seen in northwest IL. This caused a mudslide on Hwy 84 in Carroll County closing the road for an extended period of time.