Winterset tornado

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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 40–50 kn (46–58 mph; 74–93 km/h), in an area with moderate dew points, at around 50–55 °F (10–13 °C). [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.

Tornado summary

Foundation of a house that was swept away to the southwest of Winterset, Iowa, where the tornado was at peak intensity. Significant Tornado Damage in Winterset, Iowa from March 5, 2022.jpg
Foundation of a house that was swept away to the southwest of Winterset, Iowa, where the tornado was at peak intensity.

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 tracking through mainly open farmland, patches of forest, and Pammel State Park. The tornado then approached and crossed Highway 169 near the southwestern outskirts of Winterset, reaching EF4 intensity with estimated winds of 170 miles per hour (270 km/h) as it moved along Carver Road. [4] A swath of EF4 damage occurred in this area as several homes were leveled or swept from their foundations. Six people who lived on Carver Road, including four members of the Bolger family, were killed. Several other people were injured in this area as well. [5] [6] [7] Multiple other houses along Carver Road suffered major structural damage ranging from EF2 to EF3 in intensity, with loss of roofs and exterior walls observed. [4] 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, exhibiting a multi-vortex structure but causing little damage as moved through sparsely populated areas. Northeast of Patterson, the tornado produced low-end EF2 damage as it snapped hardwood trees along Highway 35. The tornado was estimated to have peak windspeeds of 112 miles per hour (180 km/h) in this area. [4]

The tornado maintained low-end EF2 strength as it entered the southeastern fringes of the Des Moines metropolitan area, moving through the outskirts of Norwalk. Several businesses and other buildings in the Norwalk area suffered heavy roof damage, the Norwalk Public Works building had its garage doors blown in, a barn was destroyed, and multiple power poles were snapped in this area. [9] The tornado then produced damage ranging from EF1 to mid-EF2 in intensity as it impacted portions of Avon and Pleasant Hill. Multiple houses in this area were heavily damaged, a few of which sustained roof loss. Outbuildings and garages were destroyed, many trees and power poles were snapped, and a MidAmerican Energy Company building suffered damage to its roof and garage doors. Continuing to the northeast at EF2 strength, the tornado became increasingly rain-wrapped as it tracked through rural areas to the south of Mitchellville. Numerous power poles were downed along this segment of the path, large farm buildings and barns were destroyed, and a two-story farm house had its entire roof torn off. Beyond this area, mainly low-end EF2 damage was observed as the tornado passed south of Colfax, snapping more power poles and destroying numerous barns and outbuildings. It then weakened to EF1 intensity as it moved through Lambs Grove and the north side of Newton. [4] Damage in Newton consisted of downed trees, damage to a baseball field, and minor to moderate structural damage. Northeast of Newton, the TPI Composites manufacturing plant had a large portion of its roof torn off at the end of the damage path shortly before the tornado dissipated. [8] [10] At least five people were injured. [11] This tornado became the first EF4 tornado to occur in 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]

Aftermath

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]

See also

Notes and footnotes

Notes

    Footnotes

    1. "Hurricanes, floods and tornadoes: The year in weather 2022". KCRA-TV. December 22, 2022. Archived from the original on 21 March 2023. Retrieved 6 February 2023.
    2. March 5, 2022 2000UTC Convective Outlook (Report). National Weather Service. Retrieved March 5, 2022.
    3. Tornado Watch #27 (Report). National Weather Service. Retrieved March 5, 2022.
    4. 1 2 3 4 "Damage Assessment Toolkit". National Oceanic and Atmospheric Administration . Archived from the original on May 19, 2024. Retrieved November 21, 2024.
    5. "Iowa family recalls deadly tornado 1 year later". WQAD. March 6, 2023. Archived from the original on 2023-03-28. Retrieved 2024-11-21.
    6. Kristianto, Josh (2022-03-07). "Crews survey damage in Winterset, Iowa, after Saturday's deadly tornadoes". KETV. Archived from the original on 2023-02-03. Retrieved 2024-11-21.
    7. Cappucci, Matthew; Bellware, Kim; Feuerstein, Jacob (March 6, 2022). "Tornado outbreak kills at least seven in Iowa with severe damage near Des Moines area". The Washington Post. Retrieved November 21, 2024.
    8. 1 2 "Family remembers those who perished in central Iowa tornado". weareiowa.com. March 7, 2022. Retrieved March 9, 2022.
    9. Rice, Trent; Danielson, Sue; Nichols, Steve; Wilde, Wendy (March 6, 2022). "Seven People Killed in Iowa Tornadoes". 1430 KASI. Archived from the original on 2022-03-25. Retrieved 2024-11-21.
    10. Houlgrave, Bryon (March 7, 2022). "4 of the 7 killed in Iowa tornadoes came from the same family, sheriff says". NPR. Archived from the original on March 7, 2022. Retrieved March 8, 2022.
    11. "Initial interrogation of photos and videos from around Winterset suggests at least EF3 tornado damage occurred late Saturday afternoon. NWS survey teams will be out Sunday to thoroughly investigate the damage and further assess a potential rating". Twitter. National Weather Service Forecast Office in Des Moines, Iowa. Archived from the original on March 6, 2022. Retrieved March 6, 2022. "NWS Damage Survey for 3/5/22 Tornado Event - Update #3". Iowa Environmental Mesonet. National Weather Service in Des Moines, Iowa. March 7, 2022. Archived from the original on March 7, 2022. Retrieved March 7, 2022.
    12. Saturday's EF4 tornado in Iowa rated state's strongest since 2013 Archived 2022-12-07 at the Wayback Machine , Washington Post, March 7, 2022
    13. Alviz-Gransee, Noelle. "It's been a year since a tornado killed 7 people in Iowa. Take a look back at the storm:". The Des Moines Register. Retrieved 2024-11-19.
    14. Ferkenhoff, Courtney Crowder and Eric. "'Stronger than before': 4 family members killed by Winterset tornado remembered as 'full of life'". The Des Moines Register. Retrieved 2024-11-21.
    15. "Sheriff: 4 of 7 killed in Iowa tornadoes from same family". NPR. March 7, 2022. Archived from the original on November 12, 2024. Retrieved November 21, 2024.
    Winterset tornado
    Winterset Tornado Wedge.jpeg
    The Winterset EF4 tornado at peak intensity to the southwest of town.