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Meteorological synopsis
On the morning of March 5, the Storm Prediction Center (SPC) issued 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, in an area with moderate dew points, at around 50-55 F. 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. 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 violent, long-track EF4 tornado, prompting the issuance of multiple PDS tornado warnings.

Tornado summary
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 then began to approach the southern outskirts of Winterset as it crossed Carver Road just south of town. Here, the tornado exhibited multiple vortices and reached EF4 strength, its point of maximum intensity. Several homes were severely damaged or destroyed, a few of which were leveled or swept away. 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. All six fatalities from the tornado occurred in the Winterset area, including four members of a family who were killed in the destruction of their home.

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. 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, Avon, 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. At least five people were injured. 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.