EF1 tornado in Pottawattamie County, Iowa

This tornado touched down two miles southeast of Minden causing EF1 damage to a transmission line. It then traveled northeast and damaged outbuildings and broke a window on the south side of a home along Tamarack Road. In addition, power poles were snapped along Tamarack Road to the northeast of this home. Tree damage continued northeast to the Avoca Rest Area where it crossed I-80. The tornado then continued north of I-80, crossing into extreme southwest Shelby County just east of the intersection of Elmwood Road and 100th Street. Peak estimated winds during this segment of the tornado track were 107 miles per hour. The maximum width was measured at 450 yards, with an average width estimated at 300 yards.

Upper air analysis depicted a negatively tilted trough over the western CONUS, with its axis extending from the central Rocky Mountains northwest into the Pacific Northwest. At the surface, a low-pressure center was deepening over the northern High Plains along with a secondary surface low in western Nebraska. Extending south out of these pressure centers was a Pacific cold front. At 21 UTC, a warm front was noted to extend southeast from southwest Nebraska into northeast Oklahoma. As the evening progressed, strong warm air advection ahead of the mature low-pressure pushed the warm front north into eastern Nebraska by 00 UTC.

Along this warm front and ahead of the Pacific cold front, several lines of strong to severe thunderstorms moved through eastern Nebraska and western Iowa. The first line of strong storms moved through central and northeast Nebraska after 4:30 PM CDT. No severe reports were associated with these storms in the OAX CWA. Another intensifying segment of the same line moved into southeast Nebraska by 7:30 PM CDT, this time south of the northward advancing warm front. These storms tracked northeast through southeast Nebraska and southwest Iowa, producing numerous severe wind gusts across the area and multiple spin-up tornadoes. The vast majority of wind gusts recorded with these storms ranged from 55 to 70 miles per hour. The strongest wind gust was measured at 71 miles per hour in Richardson County. 2 EF-0 tornadoes were confirmed in southeast Nebraska, both in Gage County. There were also an additional 3 tornadoes confirmed in southwest Iowa, all EF-1 tornadoes.