EF2 Tornado — Morgan, Indiana

2023-03-31 · near Martinsville Arpt, Morgan, Indiana

Event narrative

The rotating supercell thunderstorm's third tornado was a strong EF2 that passed immediately south of the city of Martinsville, while the supercell's non-tornadic damaging winds impacted the center of Martinsville. Numerous homes were observed with considerable roof damage in a subdivision near Indiana Highway 37, while an (empty) grain bin was lofted and displaced. The top of a concrete grain bin was torn off. The tornado continued to the east-northeast, causing sporadic tree damage through the next structure along Rolling Hills Drive. The tornado's strongest (120-130 mph) winds occurred at the end of its path, where one pontoon boat was lofted from the west side of of a lake and carried (about 800 feet) to the lake's far east-northeast point at Paris Drive. Another pontoon boat was lofted and carried about one-quarter mile and over a nearby home before final resting at another house.

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 → (39.3865, -86.4618)

Source: NOAA Storm Events Database, event_id 1089566. Narrative written by the NWS forecast office that issued the report.