Hail in Iowa, July 16, 1996

A warm front was located to the south and southwest of Iowa during the late afternoon hours of the 16th. A strong low level jet formed during the evening hours and brought very warm, moist, and unstable air north into Iowa. Dew point values at the 850 mb level were in the 16 to 18 degree C. range. Precipitable water values were in excess of 2 inches. A large mesoscale convective system developed and tracked southeast across Iowa. Severe weather occurred during the early stages of the storms development. Hail up to golf ball size was reported over west central Iowa. Crop damage as reported, as well as roof damage in Crawford and Greene Counties. There were also several reports of gusty winds. Large trees were downed at Gray in Audubon County. Shingles were removed from the roofs of houses north of Viola, also in Audubon County. One tornado was reported as well. A brief touchdown occurred northwest of Coon Rapids in Carroll County. The touchdown occurred in an open area, thus no damage was reported. Copious amounts of rain occurred during the night with the storms. A broad swath of 3 to 6 inch rainfalls extended from west central into south central Iowa. The heaviest rainfall occurred in west central Iowa with unofficial amounts near 12 inches reported in Monona and Crawford Counties. Flash flooding was widespread in Carroll and Crawford Counties where the heaviest rainfall occurred. Most of the rest of the heavy rainfall only produced urban and small stream flooding. The soil was very dry before the rain fell, thus much of what did fall soaked into the ground. Though there was some damage, it was relatively minor since much of the first several inches of rain was quickly absorbed. Some agricultural flooding was reported. Crop damage was minor as the fields were not under water for an extended period of time.