The highest low-level Vr shear values occurred as the storm moved into Iowa City from the northwest. It is during this time period, roughly 1949 to 2007 UTC, that the greatest damage occurred. TVSs were identified continuously for the next nine volume scans. A short-lived tornado was reported at 2005 UTC, but it produced no damage. TVS refers to the number of NSSL algorithm-produced TVSs during the lifetime of the vortex.
Tor denotes the occurrence or lack of a confirmed tornado with the vortex.
Since a detailed damage survey was not conducted, Tor was determined based on trained spotter reports, ground-based and aerial damage video, and public reports. N 5 Columbus Jct. Its appearance in the reflectivity and storm-relative velocity imagery was characteristic of a supercell. Outbound velocities are in red and inbound in green. Additional thunderstorms were located downstream from the Iowa City storm.