June 8, 2011: Hail in Dodge and Jefferson Counties

Increasing warm air advection and moisture transport on a 50 to 60 knot low-level jet, with increasing instability under steepening mid-level lapse rates, produced elevated thunderstorms with large hail during the early morning hours of June 8th. As the nocturnal low level inversion mixed out with daytime heating during the mid-morning hours, the storms became surface based, with damaging wind gusts as well as large hail. Additionally, the elevated nature of the showers and thunderstorms, especially in far southern Wisconsin, caused the rain underneath to evaporate before reaching the ground. The evaporated rain cooled the air below the cloud base and caused it to accelerate toward the ground, creating isolated heat bursts in Green and Rock counties with damaging wind gusts that downed trees and power lines, and also rapidly raised air temperatures 10 to 20 degrees F.