Hail in Washington County, Illinois

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.