EF0 tornado in Posey County, Indiana

The long track cell produced its third Southwest Indiana tornado on the afternoon of July 9th with an EF-2 tornado (peak of EF-0 in Posey County) that began on the north side of Poseyville, just south of I-64. Primarily crop and small branch damage occurred initially as the tornado tracked northeastward with corn fields flattened. As it approached the Gibson County line the tornado shifted to a more northward trajectory, continuing into Gibson County. Estimated peak winds with the Posey County portion of the tornado were 75 mph.

The remnants of Hurricane Beryl tracked north-northeastward to the Quad State region on the 9th, with the center of circulation following near the Lower Ohio River. The bulk of the stratiform precipitation was northwest of the Quad State, keeping flooding issues from developing. On the eastern flank of the storm, supercellular structure developed on the north end of the lakes in Kentucky, then tracked northeastward, crossing into Southwest Indiana at Mount Vernon after producing two tornadoes in Union County, Kentucky.

The first SW Indiana tornado rapidly strengthened into an EF-3 as it damaged a large Kenco facility. The tornado overturned train cars and trailers near Old Hwy 62 as it departed from Mount Vernon, causing tree damage further north. This was the first EF-3 tornado in the NWS Paducah County Warning Area (CWA) in July, with records going back to 1950. The tornado cycled multiple times in Southwest Indiana, with tornado paths beginning near Springfield (an EF-1), and again north of Poseyville (an EF-2). For the latter, the damage path broadened as it approached Johnson and leveled several structures. The Johnson tornado narrowly missed the KVWX radar, crossing 1.5 miles to the west. One last brief EF-1 tornado formed on the west side of Patoka from the primary cell. A cluster of storms further east produced a brief EF-1 tornado south of Francisco. The 7 tornadoes from this day (5 in Indiana, 2 in Kentucky) were a single day record for July tornadoes in the NWS Paducah CWA.

Effective bulk shear was near 50 kts when the tornadoes developed, while SRH was 300 m2/s2, and the supercell composite parameter was 8 for the Mount Vernon tornado and lower for subsequent tornadoes. MLCAPE was 500-1000 J/kg (higher southeast of the supercell).