Jun 19, 2009
A warm front set up across far southern Wisconsin on the afternoon of June 18th as an upper level disturbance moved eastward into the Upper Midwest. A line of severe thunderstorms formed in an area of very warm, unstable air and moved through south-central and southeast Wisconsin overnight. With surface dewpoints near 70, MLCAPE values near 3000 J/kg, and strong wind shear, the storms produced damaging winds, large hail up to 2.75 inches in diameter, dangerous lightning, and a weak tornado. Th
Source: NOAA National Weather Service Storm Events Database (event 176827). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Waukesha County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.