Damaging Wind in Iowa, August 6, 1996

A cold front progressed southeast into Iowa. Ahead of the front was a very rich air mass with surface dew point temperatures in the middle to upper 70s F., and 850 mb dew point temperatures in the middle teens Celcius. Afternoon temperatures warmed into the lower 90s resulting in CAPE values in excess of 6000 J/kg and lifted indices of -9 degrees C. Thunderstorms erupted just ahead of the cold front during the late afternoon. The storms were below severe levels through the late afternoon and evening as they crossed most of Iowa. Winds of 40 to 50 MPH were reported. There was very little hail, and that which did fall was small. The storms did produce severe winds over Cerro Gordo County. Gusts of 60 to 70 MPH were reported in the Mason City area, where a mobile home was overturned on the southeast side of town. Sixty to seventy MPH winds were also reported in Rock Falls. There was considerable tree damage there with many down.