An Examination of the Behavior of a Giant Hail-Producing Supercell in Oklahoma on 23 May 2011 Using Data from Five Doppler Radars

Abstract

Dual-polarization radar observations are valuable for identifying the location and evolution of hail in supercells. This study presents an analysis of a supercell that produced remarkably large hail [6 inches (15.24 cm) in diameter, setting a state record for Oklahoma at the time] on 23 May 2011 in the southwestern part of the state. This analysis uses data from three X-band, ground-based, mobile Doppler radars – RaXPol, MWR-05XP, and NOXP – each positioned generally to the southeast of the storm’s updraft in close proximity to each other, in addition to observations from two WSR-88Ds, KFDR located in Frederick, Oklahoma and KOUN located in Norman, Oklahoma. Of the five radars, all but the MWR-05XP and KFDR had polarimetric capabilities; the MWR-05XP, however, had rapid-scan, hybrid, phased-array technology. The investigation provides an in-depth examination of the storm's evolution, combining data analyses from all three mobile radars and the two stationary WSR-88D radars. The results of polarimetric variable comparisons, multi-Doppler wind analyses, and dual-frequency analyses will be presented. The main goal of this study is to contribute to an improved understanding of the transformation of hydrometeors, particularly hail, from their initial generation within the updraft to their eventual descent to the ground in a historic storm. A secondary goal is to document a failed attempt at tornadogenesis which was associated with a funnel cloud and examine why a tornado did not form.