Analyzing the Environment and Tracks of the six May 24, 2017 Ohio Tornadoes (338)

Andrew Hatzos, National Weather Service / Weather Forecast Office Wilmington Ohio, Wilmington, OH



On the evening of May 24, 2017, six tornadoes developed within the National Weather Service (NWS) Wilmington Ohio (ILN) coverage area. In the presence of an area of surface low pressure, these tornadoes developed within an environment characterized by copious low-level directional wind shear and ample boundary layer moisture. This led to a scenario in which instability was sufficient for updrafts and tornadoes, especially as the greatest Convective Available Potential Energy (CAPE) was focused in the lowest 3km of the convection, where wind shear was also maximized. However, this favorable environment was extremely localized, affecting only a small section of the ILN coverage area. In addition, this event was notable for the unusual direction of motion taken by the tornadoes, including what is believed to be the first southeast-to-northwest moving tornadoes ever confirmed or warned for by the ILN office. This study examines the conditions which led to the supercells and tornadoes that occurred, the radar signatures that evolved as the storms developed, and the challenging level of predictability of the event.In addition to a detailed assessment of environmental parameters and radar data, this study also involved a re-analysis of the confirmed tornado tracks. This analysis was based largely on footage and pictures taken from dozens of eyewitnesses, including video evidence of all six confirmed tornadoes. Combined with surveyed damage points and radar data, a more detailed and accurate assessment of the event was able to be completed, including refinements to start/end times and path locations.