Rapid-scan, dual-polarized observations of severe Oklahoma thunderstorms on 31 May 2013

On 31 May 2013, a dual-polarized WSR-88D located in Norman, Oklahoma (KOUN) was used to collect sectorized volumetric data in numerous severe storms, including tornadic supercells. Because only a fraction of the full azimuthal volume was observed, rapid volume update times of ~ 1 – 2 min were achieved. These rapid dual-pol observations serve as a proxy for those of a future dual-polarized phased array radar.

Through comparison with contemporaneous observations from a nearby dual-polarized WSR-88D (KTLX), which had a volume update interval of 4-5 min, we highlight a number of instances in which the rapidly-scanned KOUN radar detected or better resolved (in a temporal sense) features of severe convective storms. These observations afforded insights into the rapid evolution of severe convective storms that were not possible (or would have been made with lower confidence) with conventional scanning. In particular, we examine the dual-pol signatures of an anticyclonic tornado, merging midlevel updrafts, and a rapidly descending giant hail core. Possible implications of these rapid updates for the warning decision process will be discussed.