Thunderstorm Wind in Montgomery County, Iowa

Personal weather station measured wind gust of 72 mph.

Severe thunderstorms produced damaging wind gusts across southwest Iowa on May 17, 2026. On this day, an upper-level trough axis remained well to the west, but an embedded shortwave and attendant jet streak ejected from eastern Colorado into eastern Nebraska. At the surface, an elongated trough extended from a low in southeast Colorado through south-central Nebraska into southeast South Dakota, acting as a persistent focus for strong deep moist convergence. During the afternoon, a narrow dryline surged into central Nebraska and Kansas. East of the boundary, warm-sector dewpoints recovered into the mid-to-upper 60s, yielding a highly unstable environment with 3,000 to 4,000 J/kg of MLCAPE. Although mid-level winds were somewhat weak'resulting in unimpressive 0'6 km bulk shear'low-level hodographs featured ample cyclonic curvature. This provided sufficient low-level shear to keep updrafts organized and separated from downdrafts despite the weaker flow aloft.

A broken line of strong to severe thunderstorms developed across east-central Nebraska during the afternoon, pushing eastwards and growing upscale into a formidable wind-producing convective system. As the severe squall line pushed across the Missouri River into western Iowa during the mid-to-late evening hours of May 17, it maintained its intensity and continued to produce damaging straight-line winds. Personal weather stations across the region captured a series of severe gusts as the system swept eastward. Early in the evening, a 62 mph gust was measured near Rodney in Monona County, followed shortly by a 65 mph gust near Missouri Valley in Harrison County. As the storms progressed further southeast, the winds remained severe, with a 60 mph gust recorded near Oakland in Pottawattamie County and a localized peak gust of 72 mph measured southeast of Henderson in Montgomery County before the complex eventually exited the area.