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. However, few studies have been conducted to quantitatively answer the question: how much hail occurs at any given location? Given the coverage of WSR-88D radars over the Southern Plains and recent technological advancements including hail detection algorithms, a compilation of severe hail swaths was completed for the period spanning 2001-2003 using data from 15 radar sites across 8 states.

The Hailswath algorithm developed at Weather Decision Technologies, Inc. was used to estimate the occurrence of severe hail for each individual storm and date during the study period. The initial raw output from the algorithm was contoured to complete a coherent swath of likely severe hail. The same analysis was then performed for hail greater than or equal to 2 inches in diameter. Finally, the results of these analyses were compiled monthly, annually, and for the total duration of the study period. A thorough demonstration of the data analysis process and results will be presented. Further, the benefits and limitations of the method used to investigate the occurrence of severe hail will be explained.