Lightning Characteristics During the Merger of Two Supercell Storms on 29-30 May 2012 Observed in Oklahoma During DC3

Abstract:

The 29 May 2012 Kingfisher supercell was sampled during the Deep Convective Clouds and Chemistry (DC3) experiment. The storm was within range of the 3-D Oklahoma Lightning Mapping Array (OK LMA) and the Oklahoma City Weather Surveillance Radar 88 Doppler (WSR-88D), KTLX for its entire lifetime, but the behavior of lightning during a period late in its lifetime in which it merged with a left moving supercell storm has not been studied previously. The merger occurred toward the end of its lifetime and produced maximum flash rates of almost 500 flashes min^-1. The storm decayed rapidly following the merger. This study will focus on the electrical characteristics of the storm in the last 1.5 hours of its life: before, during, and following the merger process. Reflectivity and radial velocity data from KTLX will be used to support the discussion of lightning characteristics. Initial results show that cloud-to-ground (CG) flash rates increased markedly during the merger and increased even more following the merger. Additionally, the vertical distribution of very high frequency (VHF) source densities from lightning flashes were maintained while total flash rates decreased. The interactions of charge regions and lightning flashes between the two merging supercells will be the primary focus of this study, as well as how those interactions affected the evolution of the rates and average spatial extent of flashes and the evolution of the spatial distribution of flash initiations and CG lightning.