EF3 Tornado — Shelby, Iowa

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

Event narrative

This is a continuation of the Minden, Iowa EF-3 tornado. Prior to this segment, the tornado had tracked through Pottawattamie County and a small portion of extreme southeast Harrison County. After crossing into Shelby County between York Road and 335th Street, tree and powerline damage continued to the northeast, with a home having its roof blown off near County Road M16 and 450th Street. Trees in the area were uprooted or snapped at the base of the trunk. A home was badly damaged, and a barn was destroyed less than one mile southeast of Tennant. The tornado appears to have been widest near 750th Street and Hackberry Road, at approximately 1900 yards in width based on tree and powerline damage. At Highway 44, a home was destroyed along with substantial tree damage. Most walls of the home were standing, but a large automobile was thrown or rolled nearly a quarter mile. The tree and vehicle damage suggested that this location was a stronger section of the tornado, and was subsequently rated EF-3. The tornado tracked approximately 1.5 miles northwest of Harlan and began to turn more towards the north, significantly damaging at least 3 homes near Highway 59 as it crossed. It turned almost due north and traveled several miles along Linden Road, and missed the town of Defiance, Iowa by less than half a mile to the east. A second tornado developed just to the east of this one at this time, tracking along Oak Road and causing separate damage. Near Defiance the tornado also became rain-wrapped according to chaser video, and appears likely to have ended just south of the Crawford-Shelby county line. There is some potential based on radar data that this tornado tracked farther north into Crawford County, but damage surveys did not identify a track continuation. The peak estimated winds in this segment of the tornado track were 140 miles per hour. The maximum width of the tornado was measured at 1900 yards with an average width estimated at 1300 yards.

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 → (41.5120, -95.4980)

Source: NOAA Storm Events Database, event_id 1167528. Narrative written by the NWS forecast office that issued the report.