Flash Flood in Simpson County, Kentucky

Flooding occurred on North Main Street in Franklin, resulting in the temporary closure of the road.

During the afternoon and evening hours on September 3rd, a combination of ample moisture and sufficient instability provided the necessary ingredients for widespread convection, resulting in locally heavy rainfall and isolated wind damage reports. On the synoptic scale, a weak mid-level disturbance was located across the mid-Mississippi Valley, with a surface low located across western Kentucky. Ahead of this disturbance, a moist air mass was located across central Kentucky, with Precipitable Water values approaching, and in some locations, exceeding 2 inches during the afternoon hours on the 3rd. SBCAPE in excess of 2000 J/kg was sufficient for widespread convection, and while lapse rates and DCAPE were not particularly suggestive of widespread damaging winds, isolated wind damage was observed with the strongest storms, located across Simpson and Warren County. While severe weather was not prevalent across north central Kentucky, multiple waves of heavy rainfall from relatively slow-moving showers and thunderstorms resulted in flash flooding, particularly across Trimble, Shelby, and Franklin County. Multiple reports of road closures and damage to homes along rivers and streams were reported in the aforementioned areas.