EF1 Tornado — Harrison, Iowa

2024-04-26 · near Modale, Harrison, Iowa

Event narrative

This segment is a continuation of the EF-4 tornado that went through western Douglas and Washington Counties. Upon entering far southwestern Harrison County, the tornado moved across the Missouri River, crossing Highway 30 and the Union Pacific Rail line about one mile east of the Iowa-Nebraska state line. Several trees were snapped and broken, producing EF-0 damage. The tornado then moved across bottomland and agricultural areas, snapping or uprooting several trees and tipping center pivots, producing EF-0 to EF-1 damage. The tornado dissipated approximately 2 miles southwest of Modale, Iowa at 4:29 pm CDT. Peak estimated winds during this segment of the tornado track were estimated at 90 miles per hour. The peak width of the tornado during its track in Harrison County was estimated to be around 350 yards, with an average width of 100 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 → (41.5310, -96.0890)

Source: NOAA Storm Events Database, event_id 1167508. Narrative written by the NWS forecast office that issued the report.