Thunderstorm Wind — Marshall, Iowa

2025-07-29 · near Marshalltown Arpt, Marshall, Iowa

Event narrative

A 58 mph gust measured at Marshalltown Airport.

Wider weather episode

A thermal ridge was in place across the area, creating a hot and humid environment that was deeply unstable with MLCAPE of 3000-4500 J/kg even through the overnight hours when storms passed across Iowa. Sub-severe storms developed on the evening of July 29th associated with a stationary boundary that was draped across the state, but with little available shear they were disorganized. Meanwhile, a shortwave riding along the ridge pushed in from the west and reached western Iowa after midnight. This upper level support helped to organize the earlier convection into a line of storms in eastern Iowa while the primary line of storms organized in western Iowa. Both resulted in winds gusting 55-65+ mph as they swept across the state, leaving behind broken and uprooted trees that damaged homes in a couple cases.

View location on OpenStreetMap → (42.1100, -92.9200)

Source: NOAA Storm Events Database, event_id 1292813. Narrative written by the NWS forecast office that issued the report.