Thunderstorm Wind in Warrick County, Indiana

A very intense macroburst caused extensive damage across the county, including the Boonville area. The average width of the damage area was about three miles. The macroburst entered Warrick County from Vanderburgh County in the Stevenson and Newburgh areas. It continued east roughly along Highway 62 across Boonville to the Tennyson area. Peak winds were estimated near 120 mph. Wind speeds averaged from 60 to 90 mph, with frequent peaks over 100 mph. A damage assessment indicated roughly 100 structures were damaged, with dozens destroyed. Dozens of vehicles were damaged due to falling trees. The assessed number of damaged homes and vehicles includes Evansville and Vanderburgh County as well. Thousands of trees were uprooted, snapped, or otherwise damaged. The trees were up to five feet in diameter. Hundreds of power poles were snapped or blown over. Damage to one farmstead was estimated at over two million dollars. The specific types of damage included a mobile home that was blown off its support piers, roofing that was blown off some structures, and window and siding damage to many others. There was structural damage to some houses, barns, and a warehouse. One grain silo was destroyed. Most of the structural damage was caused by falling trees. The power company servicing the region reported 50,000 customers without power a couple hours after the storm. Numerous roads were blocked by downed trees and power lines. Numerous wires were blown down or hanging low, and telephone service was not reliable. The total length of the damage area across Vanderburgh, Warrick, and extreme western Spencer Counties was 35 miles. The average width of the damage area was three miles, with a maximum width of four miles.

A major macroburst with winds over 100 mph at times caused extensive damage in the Evansville area. Thunderstorms intensified and evolved into a bowing structure that spread east across southwest Indiana. The storms developed ahead of a cold front extending from northern Indiana southwest across central Illinois into southeast Missouri. Convergence in the vicinity of the cold front, where the environment remained moderately unstable, supported thunderstorm development. Bulk wind shear was strong enough to support organized severe storm structures.