Tornado and Hail in Iowa, June 23, 2000

A very unstable airmass was in place across Iowa during the morning of the 23rd. Thunderstorms erupted by the late morning hours as an upper level disturbance advanced into the state from the west. A small cluster of thunderstorms formed in as the mesoscale convective vorticity center from a round of convection over the high plains the previous night moved into air with CAPE values around 4000 J/kg. A warm front was lifting north across the state as well with surface dew points in the mid 70s to the south of the front. Although there were some reports of some small hail, less than in inch in diameter, from the storms; the main weather feature from these storms was high winds. The strongest winds occurred in Indianola as a microburst resulted in a wind gust of 109 MPH. High winds caused considerable tree damage and some building damage across south central Iowa as the cluster of storms moved east. A mobile home was knocked off of its foundation in the Moulton area as the storms moved through. One small tornado touched down briefly in Wayne County near Corydon. No significant damage was reported with this tornado. The same cluster of storms that moved across the far southern tier of Iowas counties produced high winds to the north of it. In Lucas County, strong south winds flowing out of the cluster caused damage on a farm near Chariton. A machine shed was destroyed with pieces of the building swept downwind for about one half mile.