Using Doppler radar to more accurately predict the occurrence of severe hail in the Arkansas-Louisiana-Texas region

The National Weather Service officially changed the hail criterion for severe thunderstorms from 19.0 mm (0.75 in.) to 25.4 mm (1 in.) on 5 January 2010. A change to the hail warning methodology was necessary to account for this change in the criterion. Recent studies for the Northern Plains and the Mid-Atlantic regions focused on the correlation between the maximum height of the 50 dBZ core and the height of the freezing level with the occurrence of severe hail. Using archived Level II data since 2007 from the NEXRAD network, rawinsonde observations, and damage reports from the NWS Storm Prediction Center, similar correlations were computed for the Ark-La-Tex region to assist in the warning decision-making process. Results from this study are expected to increase warning accuracy by leading to higher probabilities of detection of severe hail and a decreased false alarm rate of warnings.