EF1 Tornado — Shelby, Iowa

2024-04-26 · near Defiance, Shelby, Iowa

Event narrative

This tornado touched down less than a mile southeast of Defiance, Iowa just north of the Linden Road and Knotty Pine Road Intersection. Here, a roof was blown off a barn and several tree trunks in the area were snapped. The tornado moved to the northeast, skirting the town of Defiance by less than a mile to the east. A home at the intersection of Linden Road and 2300th Street received minor roof damage and had its car garage completely destroyed. This was the worst damage from this tornado in Shelby County, warranting an EF-1 rating with max wind speeds estimated at 105 miles per hour. Another large barn at the intersection of Street F16 and Mulberry Road had large sections of its roof damaged. At 1753 CST, the tornado crossed into Crawford County half a mile west of 300th Street. At this point in time, EF-1 damage was still being done with several tree trunks being snapped with the passage of the tornado. The peak width achieved by this tornado in Shelby County was 300 yards, with an average width of 200 yards. This tornado continued into Crawford County and produced additional EF-0 and EF-1 damage until it dissipated 6 miles north-northeast of Manilla, Iowa.

Wider weather episode

On the morning of April 26th, a potent negatively-tilted shortwave trough ejected out into the central Plains. Upper air analysis shows a jet streak on the downstream side of this trough with substantial divergence aloft over Nebraska. At the surface, morning cloud cover and drizzle across much of eastern Nebraska and western Iowa quickly gave way to partly cloud skies as a warm front moved north through the area, just after noon. At the same time, thunderstorms initiated along a pacific front/dryline in south-central Nebraska. One supercell produced several tornadoes from south-central Nebraska into Boone County, resulting in an EF-2 tornado just west of Cedar Rapids. A second round of supercells initiated in Jefferson and Saline counties. These long-track supercells produced the worst tornado outbreak the Omaha WFO has seen in 10 years. 5 EF-3 tornadoes were surveyed, with several of these tornadoes just shy of an EF-4 rating. One of these EF-3 tornadoes impacted the northeast side of Lincoln, Nebraska where 70 people were reported trapped in a manufacturing plant that collapsed as the tornado passed. Another long-track EF-3 tornado hit portions of Elkhorn, Bennington and Blair, Nebraska. Eppley Airfield was hit by the third EF-3 tornado of the day, doing damage to aircraft hangars on the southeast side of the airport before hitting homes in far western Pottawattamie County. The last two EF-3 tornadoes of the day both impacted portions of Pottawattamie County. While one remained primarily in rural areas in the central part of the county, the final EF-3 of the day hit the town of Minden, Iowa head-on, resulting in 1 fatality and 3 injuries. This was the only fatality of the entire event. This tornado continued into Shelby County, narrowly missing the towns of Tenant and Harlan. A total of 24 tornadoes were confirmed across both Nebraska and Iowa portions of the Omaha CWA. The strongest tornado was the EF-3 that impacted Elkhorn and Blair, with peak estimated wind speeds at 165 miles per hour.

View location on OpenStreetMap → (41.8200, -95.3400)

Source: NOAA Storm Events Database, event_id 1167529. Narrative written by the NWS forecast office that issued the report.