EF1 Tornado — Harrison, Iowa

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

Event narrative

A tornado developed in woodlands about 4 NNW of Magnolia, IA. Road maintenance workers noted damage to the trees south of 174th Trail Road on the south side of Steer Creek. The tornado crossed 174th Trail breaking power poles and damaging a farmstead. The tornado moved generally north moving across agricultural fields and skirting the eastern periphery of the Loess Hills State Forest west of Juneau road, damaging a house and trees. The tornado veered to the NNE, crossing 154th Trail Road, where it moved across an impassable area of Loess Hills State Forest west of Kelsey Avenue. It crossed just south of the intersection of Kelsey Avenue and Easton Trail Road, causing damage to a farmstead and power poles. It continued to move NNE, snapping trunks and large branches of trees and destroying barns and outbuildings along 110th Street, as well as along Laredo Avenue north of 112th Trail Road. The tornado began to weaken as it approached the Harrison-Monona county line, producing only very minor damage as it moved into Monona County east of Peach Avenue. The peak estimated winds in this tornado for this segment of its track were 110 miles per hour. The maximum width achieved by the tornado was 766 yards, with an average width during this segment estimated at 450 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 → (41.7500, -95.9100)

Source: NOAA Storm Events Database, event_id 1167509. Narrative written by the NWS forecast office that issued the report.