| Width: | 300 |
| Duration: | 1 hour, 34 minutes |
| Formed: | March 5, 2022, 4:26 p.m. CDT |
| Dissipated: | March 5, 2022, 6:00 p.m. CST (UTC−06:00) |
| Winds: | 170mph |
| Fujita-Scale: | EF4 |
| Tornadoes: | 1 |
| Fujita-Scale: | EFU |
| Header: | Satellite tornadoes |
| Fatalities: | 6 |
| Injuries: | 5 |
| Damages: | $220 million (2022 USD) (Costliest tornado in 2022)[1] |
| Part: | the Tornado outbreak of March 5–7, 2022 and Tornadoes of 2022 |
In the afternoon hours of March 5, 2022, a large and violent tornado hit Winterset, located near Des Moines in the state of Iowa. The tornado produced heavy damage, and received an EF4 rating as a result. The tornado was the most powerful to touch down during the tornado outbreak of March 5–7, 2022, and the costliest tornado of 2022, inflicting $220 million (2022 USD) worth of damages to the areas it impacted.
The tornado first touched down near Macksburg, moving northeast while rapidly strengthening. As the tornado crossed Highway 169, it reached EF4 intensity, killing six people who were living on Carver Road, located to the southwest of Winterset. The tornado would continue to produce heavy damage as it tracked towards Winterset, eventually grazing the southern edge of the town before passing near Patterson. The tornado would continue to move through rural areas, eventually moving past portions of Des Moines before lifting.
On March 4, the Storm Prediction Center (SPC) issued a slight risk outlook for severe weather for a negatively tilted shortwave trough positioned over the High Plains. The outlook included the possibility of strong winds, large hail, and a 5 percent chance for tornadoes, mostly throughout southern Iowa. The next day, the SPC upped their alert level to an enhanced risk, centered in Iowa, as a stronger certainty arose for severe weather. The probabilities for damaging winds were increased to 30 percent, and the probabilities for tornadoes were elevated to a 10 percent, unhatched area (indicating a <10% chance of EF2 or stronger tornadoes) centered along southwestern Iowa. The outlook referenced an increase in destabilization, coupled with a modest low level jet at around, in an area with moderate dew points, at around .[2] At noon, the SPC issued its first tornado watch, for southern Iowa and northwestern Missouri, discussing the moderate probabilities for tornadoes to occur, although a major tornado outbreak was not expected.[3]
As the afternoon advanced, multiple supercell thunderstorms developed in the area of concern, rapidly developing into powerful, tornadic storms. One of these cells became dominant over southwestern Iowa, producing two weak tornadoes. It recycled its mesocyclone and produced the Winterset tornado.
The tornado first touched down near the intersection of Deer Run Avenue and 280th Street to the north of Macksburg. Moving northeast, the tornado began to rapidly intensify while traversing mainly open farmland and forest. The tornado would continue to strengthen as it moved across the Pammel State Park. As the tornado crossed Highway 169, it reached EF4 intensity for the first time as it directly impacted a home, obliterating the structure while retaining winds that were estimated to be up to 170mph.[4] Trees in the area were snapped, and other homes located along Highway 169 also sustained varying degrees of damage, including a home that was almost destroyed by the tornado; damage at the home was later given an EF3 rating. The tornado would continue to move to the northeast, striking Carver Road, where heavy damage was documented. Six people who lived on Carver Road, including four members of the Bolger family, were killed as the tornado moved parallel to the road; several more people were injured as the tornado passed over.[5] [6] [7] Cars were flipped and thrown, outbuildings were obliterated, debris was strewn long distances, and many large trees were snapped and denuded in this area as well.[8]
After the large and destructive tornado exited the Winterset area, it continued to the northeast and passed through rural areas near Patterson, continuing to exhibit a multi-vortex structure but causing little damage as moved through sparsely-populated areas. Northeast of Patterson, the tornado produced a line of EF2 damage as it moved through, including damage to trees located off of Highway 35 and electrical transmission towers. The tornado was estimated to have peak windspeeds of 115mph in this area,
The tornado then weakened some but remained strong as it tracked through the southeastern fringes of the Des Moines metropolitan area, moving through the outskirts of Norwalk. Several buisnesses and other buildings in the Norwalk area suffered heavy roof damage, and a barn was obliterated by the tornado as it moved through.[9] The tornado would then strike the far-north portions of Avon, damaging several homes and Pleasant Hill. Homes in this area sustained major structural damage, outbuildings, and garages were destroyed, many trees and power poles were snapped, roofing was torn off of a manufacturing plant, and the Norwalk Public Works building had its garage doors blown in. Continuing to the northeast, the tornado became increasingly rain-wrapped, downing more power poles and causing additional damage to homes as it passed south of Colfax, and then weakened further as it moved through Lambs Grove and the north side of Newton before dissipating.
Damage in Newton consisted of downed trees, damage to a baseball field, and minor to moderate structural damage. The TPI Composites manufacturing plant had a large portion of its roof torn off near the end of the damage path.[10] At least five people were injured.[11] This tornado became the first EF4 tornado to affect Iowa since October 4, 2013, was the deadliest tornado in Iowa since May 25, 2008, the longest tracked tornado in Iowa since April 27, 2014, and the northernmost confirmed violent tornado so early in the season.[12]
50 homes were damaged in the area, with 35 or 40 sustaining major damage. A total of seven fatalities were recorded, with two of them being children.[13] Four of these fatalities were members of the Bolger family, who were killed when the tornado directly impacted the home that they were sheltering in; several more in the house were seriously injured.[14] [15]