National Centers for Environmental Information reports:
This is the first segment of this devastating tornado which passed through four counties including Madison, Warren, Polk and Jasper. The tornado began northwest of Macksburg in western Madision county. The tornado remained in mostly rural cropland and wooded areas of western Madison county. The tornado passed through Pammel State Park southwest of Winterset producing extensive tree damage as the tornado continued to widen into a wedge tornado. Upon exiting the park, the tornado travelled along Carver Road. Several residential homes were extensively damaged or destroyed along Carver Road and six deaths occurred along this stretch of road. The tornado was at peak intensity at this time with EF4 damage occurring west of the intersection of Carver Road and Highway 169 with a house completely destoyed and removed from the foundation. After departing the Carver Road corridor, the tornado progressed just southeast of Winterset and eventually passed east of town and crossing State Highway 92. Damage in these areas was primarily to trees and outbuildings although a few homes were also impacted with mostly EF1 to EF2 damage. From Highway 92 to where the tornado exited the county, it remained mostly in rural cropland and wooded areas with numerous trees impacted. The tornado then moved into Warren county from Madison county.
The tornado remained very broad with a maximum width of up to 500 yards at times. Video evidence supports a multi-vortex circulation with the tornado across much of Warren county. The tornado cross Interstate 35 shortly after entering the county but fortunately, no vehicles were impacted. The tornado remained in rural areas to the west southwest of Norwalk producing mostly tree and outbuilding damage. The tornado passed along the southeast edge of Norwalk producing EF0 to EF1 damage along Coolidge Street and along Highway G14 near Warrior Run Golf Course. The tornado crossed Highway 5 just west of the intersections of Highway 5 and Highway 69 approaching the southeast side of Des Moines. The tornado entered into Polk county shortly after crossing Highway 69 near the intersection of Highway 69 and Indianola Avenue.
This tornado passed from Warren county into Polk county near the intersection of Highway 69 and County Line Road. The tornado crossed E Pine Avenue removing the roof of a house and then clipped the north edge of Avon producing EF2 damage to a couple of houses. The tornado then crossed the Des Moines River and impacted the Woodland Hills neighborhood damaging muliple structures. The damage continued to the northeast into less inhabited areas of eastern Polk county, however the tornado remained strong with EF2 damage at several locations along its path. The tornado crossed University Avenue near its intersection with NE 112th Street and then exited the county into Jasper county.
The tornado moved into Jasper county from Polk county. The tornado remained largely in rural areas for much of its path across Jasper county. Despite its rural venture, the tornado impacted several residences in western Jasper county producing several areas of EF2 damage. The tornado did pass not far from the southeast side of Colfax damaging structures near the intersection of Highway 117 and S 44th Avenue West. The tornado crossed Interstate 80 east of Colfax near mile marker 160 and then proceeded towards Newton, grazing both the communities of Lambs Grove and Newton on the north sides. Most of the damage was to trees and minor damage to structures including loss of shingles and broken windows. The tornado did remove about a 100 foot segment of the roof of the former TPI Composites Plant northeast of Newton with the tornado dissipating shortly thereafter. In all, the tornado had a path length of just over 70 miles and passed through four counties including Madison, Warren, Polk and Jasper. The six deaths were the most by a tornado in Iowa since the Parkersburg tornado in May of 2008. The damage was into the hundreds of millions of dollars.
