EF1 Tornado — Shelby, Iowa

2023-07-12 · near Portsmouth, Shelby, Iowa

Event narrative

A tornado developed just north of 1150th street and east of Highway 191 where it destroyed two barns and damaged others. The tornado track continued east with evidence of convergent flow pattern within the debris field and the cornfield as it tracked to the east.

Wider weather episode

A widespread significant damaging wind storm tracked across nearly all of eastern Nebraska and western Iowa on the morning of July 12. These storms produced widespread winds of 60 to 80 mph, with embedded stronger downbursts with wind speeds up to 100 mph. The strongest measured wind gust was 82 mph in Dodge County NE, but some of the high-end straight line wind damage supports embedded wind speeds up to 100 mph.

This storm also produced a few embedded tornadoes. Some of the tornado tracks were only identified by narrow swaths of damage through mature cornfields, with minimal damage otherwise and peak wind speeds similar to the nearby downburst winds. All but one of the tornadoes was preceded by a Wireless Emergency Alert. There were 0 reported injuries or fatalities.

View location on OpenStreetMap → (41.6690, -95.4950)

Source: NOAA Storm Events Database, event_id 1114266. Narrative written by the NWS forecast office that issued the report.