Hail and Damaging Winds in Iowa, July 3, 2001

Moist and unstable air lifted north into Iowa during the day on the 3rd. Dew points 24 hours prior to the event ranged from the upper 20s to the low 50s across the state. During the night of the 2nd and day of the 3rd, dew point temperatures rose into the mid 60s to low 70s. Surface temperatures rose into the 80s to low 90s across the state. This produced CAPE values in the 2000 to 4000 J/kg across the state by the mid afternoon hours. A warm front inched into southern Iowa during the afternoon while at the same time a cold front was dropping southeast across the state from the northwest. A small area of high CAPE values over 5000 J/kg was present over south central Iowa. Thunderstorms erupted just south of the Des Moines metropolitan area by the mid afternoon hours. The cluster moved south during the afternoon and exited the state by evening. The severe weather event of the day was hail. Large hail developed within 10 to 15 minutes of the first echo. Numerous areas reported hail in excess of an inch in diameter, with several reports lager than golf ball in size. Hail 4 inches in diameter pounded the town of Truro in Madison County, causing extensive damage. Three inch diameter hail fell in Marion County in rural Otley. Extensive damage occurred in the town of Osceola with two and one half inch diameter hail falling there. There was little in the way of wind damage from the storms. A few reports were received, mainly toward the end of the event as the storms began to collapse. During the early part of the event, high winds south of New Virginia in Warren County toward Osceola in Clarke County caused damage in a two to three mile wide area. Trees were downed, several road signs were blown over, and some light structural damage was reported across the area. Late in the storms life cycle, 65 MPH winds were reported in Decatur City of Decatur County. A collapsing cell caused damage south of Kellerton in Ringgold County just before the storms moved out of the state. Trees and power lines were downed and a grain bin was blown 300 meters off of its foundation. During the 15 minute event, a motor home was rolled over by the high winds as well.