Geostationary Lightning Mapper and Rapid Update Polarimetric Radar Observations of Tornadic and Nontornadic Quasi-Linear Convective System Mesovorticies

With the advent of rapid-update polarimetric radar data and the GOES geostationary lightning mapper (GLM) comes the opportunity to assess atmospheric phenomena in greater detail than with previously available operational data. Understanding of quasi-linear convective system (QLCS) tornadoes especially stands to benefit. Developing rapidly in the lowest kilometer of the atmosphere, detection is difficult using traditional velocity and tornadic debris signature based methods. Lightning jumps and ZDR column height have been correlated to updraft strength and may be potential precursor signatures since increasing updraft intensity can enhance low level stretching of vertical vorticity. Also, tornadogenesis and mesovortexgenesis within QLCS’s is theorized to be heavily dependent upon downbursts driving intensification of the rear inflow jet, which is evident from descending reflectivity cores and subsequent increases in velocity. In this study, data from the rapid-scan, polarimetric research radar in Norman, Oklahoma (KOUN) is used in conjunction with GLM data to assess tornadic and non-tornadic mesovorticies in two central Oklahoma QLCS events. KOUN data does a sectored scan with an update time of 2 minutes, and GLM detects flashes on the order of 2 milliseconds with updates every 20 seconds. Mesovortexgenesis times and locations will be identified, and tornado presence will be verified by via the NCEI Storm Data database. Lightning jump locations spatially and temporally to the mesovortex will be assessed, and ZDR column heights will be calculated. Descending reflectivity cores will be identified as well. These signatures will be compared to the tornadic circulations to assess their utility and then compared with the non-tornadic cases. The lead author will present results from this ongoing study.