A long lived supercell thunderstorm tracked across northern Iowa Sunday morning with the Highway 20 corridor receiving the brunt of the damage. Reports of quarter to golf ball sized hail were common with some hail stones reported to be in excess of two inches approaching the size of a tennis ball. The hail was wind blown as well, at speeds of 50 to 70 mph, making it extremely damaging and dangerous striping siding off houses and knocking out windows. A measured wind speed of 68 mph was recorded at a KCCI TV SchoolNet site near Jewell in Hamilton County. Significant hail damage was received all along the track with areas near Otho, Callender, Radcliffe, Eldora and Grundy Center hit particularly hard. Several minor injuries were reported in Hardin County.
The radar loop below was provided courtesy of the Iowa State University / Iowa Environmental Mesonet and show the storms movement and damage reports roughly between 800 am and noon.
The following images were provided courtesy of the Fort Dodge Amateur Radio Association and show damage in the Otho and Callender areas.