May 11, 2011: Hail in Dane, Jefferson and Waukesha Counties

Strong to severe thunderstorms developed as lift associated with a 500 mb short wave moved into southern Wisconsin. The short wave eroded a cap on a moist and unstable air mass, with mixed-layer CAPE values of 2,000 to 3,000 J/KG, and enough deep-layer shear for sustained updrafts. There were numerous reports of large hail in the 1 to 2 inch range with the severe thunderstorms, with 4-inch hail reported in Jefferson County. While no specific damage reports were made to officials, the Jefferson County Emergency Management Director stated some properties might have received damage from the large hail, such as dents to vehicles.