The Evolution of a Severe Mesoscale Convective System: Cloud-to-Ground Lightning Location and Storm Structure

Abstract
Cloud-to-ground lightning-location data are correlated with the Doppler-radar-observed structure of the evolution of a severe mesoscale convective system in Oklahoma on 23 May 1981. While many of the results are not new, this study is unique in that the evolution of electrical activity in a severe storm is compared to storm structure for most of the storm's life. The, first storm formed ahead of a mesoscale low pressure area located at the intersection of a front and a dryline, and developed into a tornadic supercell in an environment of locally enhanced vertical shear. Ordinary cells subsequently formed both to the southwest and northeast of the supercell along the dryline and the front, respectively, and merged with the supercell to form a squall line having a trailing stratiform precipitation region with midlevel rear inflow. It is shown that the cloud-to-ground flash rate in the convective region is related to the apparent strength of the updraft. Before the storm became a supercell, the ligh... Abstract Cloud-to-ground lightning-location data are correlated with the Doppler-radar-observed structure of the evolution of a severe mesoscale convective system in Oklahoma on 23 May 1981. While many of the results are not new, this study is unique in that the evolution of electrical activity in a severe storm is compared to storm structure for most of the storm's life. The, first storm formed ahead of a mesoscale low pressure area located at the intersection of a front and a dryline, and developed into a tornadic supercell in an environment of locally enhanced vertical shear. Ordinary cells subsequently formed both to the southwest and northeast of the supercell along the dryline and the front, respectively, and merged with the supercell to form a squall line having a trailing stratiform precipitation region with midlevel rear inflow. It is shown that the cloud-to-ground flash rate in the convective region is related to the apparent strength of the updraft. Before the storm became a supercell, the ligh...