EF3 Tornado — Monroe, Indiana

2023-03-31 · near Stinesville, Monroe, Indiana

Event narrative

Continuation from Owen County of the rotating supercell thunderstorm's second EF3. The tornado reached peak intensity while crossing the Owen-Monroe County line, where the strongest winds in Monroe County were 152 mph along West Wolf Mountain Road. Here, 0.2 to 0.3 miles east of North County Line Road, the tornado destroyed both a mobile home and single story homes with little anchoring on cinder blocks, among many damaged and debarked trees. Back closer to North County Line Road, and slightly farther north of the center of the tornado's path, winds had separated a trailer home from its attached structure and garage, allowing the home to roll and flatten. Farther east along West Wolf Mountain Road, EF2-intensity damage was observed 0.50 to 0.75 miles east of the county line, with areas where nearly all trees were uprooted or snapped, and several single-family homes lost large sections of roofing; a few debarked trees were observed, but with less frequency than seen closer to the county line.

The tornado continued for another 2.7 miles while gradually weakening through EF2 and EF1 intensities. At North Texas Ridge Road hardwood trees were snapped off while a few homes lost small portions of roofing. At the intersection of West Brighton Road and North Fulton Road a narrower corridor of smaller trees were snapped or uprooted, including one tree downed onto a house; the tornado track ended about 250 feet northeast of this intersection.

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 → (39.3089, -86.6854)

Source: NOAA Storm Events Database, event_id 1089811. Narrative written by the NWS forecast office that issued the report.