EF1 Tornado — Montgomery, Indiana

2023-03-31 · near Bowers, Montgomery, Indiana

Event narrative

This squall line tornado began in far northeastern Montgomery County, approximately midway between the communities of Darlington and Colfax, (while, a weaker EF0 tornado was simultaneously spawned about 1.5 miles to the southeast). The tornado first downed trees (uprooted hardwood and snapped pines) in a distinct 0.5-mile long patch along Withe Creek prior to crossing East Bowers Road, consistent with EF1-intensity winds as high as 94 mph. The tornado then continued into Boone and Clinton Counties where it would ultimately reach EF2 intensity.

Wider weather episode

A strong, occluding storm system over the Upper Midwest produced a deep column of strong southwesterly winds over the Midwest on the afternoon and evening of the 31st.

This pattern generated an inordinate amount of vertical wind shear. The overall southwesterly flow also brought rather mild and somewhat humid air into the region, which was adequately unstable given noticeably colder air aloft, especially over the southwestern quadrant of Indiana.

Resulting thunderstorms were able to mix down the stronger winds to the surface as damaging straight line gusts, while a rather low freezing level promoted isolated large hail. Ten tornadoes occurred across the region: 5 from a rotating supercell thunderstorm that tracked roughly parallel to and about 20 miles south of Interstate 70, and 5 others spawned from a squall line's northern book-end vortex that impacted north-central central Indiana. The supercell's first two tornadoes (both EF3) caused a combined 5 fatalities...before the supercell spawned two more strong tornadoes (EF2/EF3), with the cell's final EF3 inflicting major damage on a warehouse in Whiteland (Johnson Co.). The (northern) squall line's first tornado was an EF2 that impacted mostly rural areas...while the squall line's four following tornadoes were all weak (EF0/EF1), with the final three spawned over Howard County, concluding with a longer tracking EF1 that injured one person.

View location on OpenStreetMap → (40.1540, -86.7171)

Source: NOAA Storm Events Database, event_id 1089563. Narrative written by the NWS forecast office that issued the report.