Hail in Iowa, June 29, 1997

A very unstable air mass was in place over Iowa with lifted indices near -12 degrees C and CAPE values around 4500 J/kg. Two features moved into the state. The first was an outflow boundary from a mesoscale convective system that had been over South Dakota and southwest Minnesota the previous night. The second was a mesoscale covnective vorticity maximum moving into eastern Nebraska. Thunderstorms developed along the ouflow boundary and also with the vorticity maximum. Most of the storms were not severe, but did produce heavy rainfall of 2 inches per hour and pea size hail along with wind gusts to around 40 MPH. There were several reports of local urban flooding in towns. Some of the worst was in Waterloo, however no significant flooding occurred. There were two storms that became severe. One developed a well developed meso on the WSR-88D over Webster County. No tornado occurred, however there was a brief gust to 60 MPH in the town of Gowrie. Farther east along the outflow boundary, another storm dropped large hail over northern Butler County. Golf ball size hail occurrred briefly east of Greene. Outside of the storms and rain, there were numerous reports of funnel clouds, however none of the threatened to touch down.