Thunderstorm Wind in St. Louis (c) County, Missouri

Widespread wind damage across the northern portions of the city as a line of storms moved through. Numerous large trees, tree limbs, power poles and power lines were blown down. A woman who was waiting for the storm to pass was killed when a large tree was blown over, crushing the car in the alley of the 4100 block of Chouteau Avenue. Two historical cemeteries, Calvary and Bellefontaine, sustained widespread damage. Around 100 trees at Calvary and nearly 40 significant trees and 100 smaller ones at Bellefontaine, were either uprooted or snapped off near the base, as well as numerous tree limbs. Several gravestones were either damaged or destroyed by fallen trees and/or tree limbs. A large tree was uprooted in the 3000 block of Longfellow Boulevard, landing on a house causing major roof damage. A couple of power poles were snapped off along Hall Street. Over 100,000 customers (St. Louis County/St. Louis City) were without power due to this storm. It took a little over 4 days to restore power to all of them.

Even though an old outflow boundary was across southeast Missouri and the far southern portions of Illinois during the morning hours, the boundary dissipated, allowing 75+ dew points to surge north along the Mississippi River. As skies cleared the atmosphere was able to quickly destabilize. Surface based CAPEs were in excess of 3000 J/kg with 40kts of 0 to 6km bulk shear. This combined with a shortwave trough that moved eastward across the region, produced strong to severe storms. There were numerous reports of damaging winds and some reports of large hail. There were three fatalities due to fallen trees.