A powerful thunderstorm supercell that formed in central Iowa County on the humid afternoon of Wednesday, July 16t, continued into northwestern Dane County, spawning an EF1 and EFO tornado in its wake. The most damage could be found in Roxbury Township, in Dane County, where 20 to 40 tree limbs were taken down in one area, according to the National Weather Service, and winds reached 80 miles an hour.