Formation and track into Parkersburg The southern supercell in a cluster of rapidly intensifying cells began rotating in northeast
Iowa, west of
Waterloo. The first tornado warning of the cell was issued at 4:22 pm CDT (21:22 UTC), encompassing the
Parkersburg area. As a tornado-cyclone materialized, a funnel cloud developed, and a tornado touched down two miles south of
Aplington near the
Butler and
Grundy County line at 4:48 pm CDT.East of Aplington, the tornado traveled through a series of farm fields, leaving distinct
cycloidal marks in the corn stubble. The tornado rapidly grew in size right after touchdown, and wind-rowing of grass and farm debris indicated a violent vortex. It then tracked into Parkersburg, becoming extremely violent, intensifying to EF5 strength, and growing into a large wedge-shaped tornado as it tore through the southern part of the community just before 5:00 pm CDT. Numerous homes and businesses, two banks, and a high school were destroyed as the south side of Parkersburg was essentially flattened. As the tornado entered town, a large and well-constructed metal frame industrial building that was being converted into a church was obliterated at EF5 intensity, with the structure's metal beam frame mangled into a pile and pushed off of the foundation. Beams were twisted and sheared off at their bases at this location. Residential areas in Parkersburg were devastated at EF5 strength by the tornado, as whole neighborhoods were leveled and entire rows of homes were swept away, leaving only basements behind in some cases. Some of the homes swept away in town were bolted to their foundations. A rebar support set into the foundation of one home was found snapped in half, hardwood trees throughout southern Parkersburg were completely debarked and denuded, and shrubs were uprooted and stripped in some areas as well. Aplington-Parkersburg High School sustained EF4 structural damage, and reinforced concrete light poles near the school were snapped and dragged along the ground by the tornado, indicative of extremely intense low-level inflow winds. As the tornado exited at the east side of town, the tornado struck a golf course and a newly built subdivision. Multiple large and well-built homes with anchor bolts were swept completely away at that location. Two of these homes had no visible debris left anywhere near the foundations, one of which was built "with above standard construction methods." At one home that was swept away in this subdivision, a concrete walk-out basement wall was partially pushed over, and the concrete basement floor sustained cracking. Structural debris from the town was wind-rowed in long streaks through fields in this area, with much of the debris finely granulated into small fragments, some no larger than coins. The tornado was estimated to have been about wide as it struck Parkersburg. Seven people died in town, several of which were taking shelter in basements.
New Hartford After passing through Parkersburg, the EF5 tornado continued eastward towards the neighboring town of
New Hartford. Tree damage between the two towns was almost complete, with rows of trees being blown over and ripped from the ground, root and stem. Pavement was peeled from the ground along Highway 57, and telephone poles still remain slanted towards the direction of the funnel to this day. Ground scouring during this phase was intense, with the deep cycloidal marks found in crop fields being some of the worst ever documented. Additional rural homes were obliterated and swept away in this area, and a granary was destroyed. The tornado maintained EF5 strength as it reached New Hartford, impacting a housing development on the northern side of the town at 5:09 pm CDT. Multiple well-built homes with anchor bolts were again completely swept away, and vehicles were thrown long distances and mangled beyond recognition, a few of which only had their frames left. One home in this area had even its basement contents swept away, including the home-owner who was killed. Numerous headstones were toppled at the New Hartford Cemetery, and shrubs and trees were completely debarked. The tornado was likely capable of producing EF5 damage for the majority of its life up until it exited New Hartford.
Weakening, track near Waterloo and dissipation Past New Hartford, the tornado weakened dramatically and passed just north of
Waterloo and
Cedar Falls, shrinking to about in width as it continued to impact rural areas. Damage along this section of the path was mostly minor, though a few farms sustained EF2 damage. Intense cycloidal marks were again noted in farm fields in this area. As the tornado approached
Dunkerton, it turned to the east-northeast, missing the town and growing up to wide. Some re-intensification occurred in this area, as consistent high-end EF2 damage was noted at multiple farms. Numerous hog containment buildings were destroyed, and a few homes that were impacted sustained some collapse of exterior walls. Mud and corn stubble was picked up from farm fields near Dunkerton and plastered thickly against fences, power poles, and houses. Shortly before reaching
Fairbank, the tornado abruptly dissipated. == Aftermath ==