An analysis of severe hail swaths in the Southern Plains of the United States

Severe hail is a common event in the southern plains of the United States. Given the coverage of WSR-88D radars over the southern plains and recent technological advancements including hail detection algorithms, a climatology of severe hail swaths is currently being developed. Data from 15 radar sites across 8 states are analyzed for the period spanning 1998-2004.

To compile a list of potential study cases, Storm Data hail reports for Oklahoma, Texas, New Mexico, Colorado, Kansas, Missouri, Arkansas and Louisiana were gathered for the study period. Any dates with at least one hail report were included in the study as a hail day. Next, using the WSR-88D reflectivity data, the Hailswath algorithm developed at Weather Decision Technologies, Inc., and Storm Data reports, hail swaths were plotted across the region for each candidate hail day. The swaths were then contoured manually and smoothed to merge the individual radar scans into a coherent and concise swath. Finally, the spatial and temporal characteristics of the individual hail swaths are analyzed to determine their length, width, and total area. Finally, the geographic location as well as the seasonal and inter-annual variability are examined.