Comparisons between Supercell Kinematics and Lightning Optical Energy Output from GLM

The Geostationary Lightning Mapper (GLM) provides a unique opportunity to utilize additional properties of lightning to monitor convective intensity. Previous work has demonstrated a strong correlation between rapid increases in total lightning (also known as lightning jumps), thunderstorm updraft strength and size, as well as, the utility of this information to predict the onset of severe weather. Both optical energy and flash size are two properties that GLM can provide routinely across the instrument’s entire field of view; however, very little work has been done to demonstrate the relationship between a thunderstorm’s optical output and thunderstorm’s intensity. Herein, this study examines the relationship between kinematics, microphysics, and observed optical energy output using GLM, polarimetric radar, dual-Doppler synthesis, and when available, lightning mapping array data. The goal of this study is to relate characteristics in updraft intensity retrieved through a dual Doppler analysis from ground based and airborne radars to the optical energy output observed from GLM.

One particular focus of this study is the 22 April 2017 tornadic supercell which produced copious amounts of hail greater than 2.5 cm and an EF 0 tornado with a path length of 3.5 km along the southern edge of Skyline, AL. The supercell was sampled during the Verification of the Origins of Rotation in Tornadoes Experiment - Southeast (VORTEX-SE) project and the GOES-16 Validation campaign. Two ground based radars and an airborne tail X-band radar from the NOAA P3 were able to capture the supercell producing large hail and the tornado. Additionally, NASA’s ER-2 aircraft provided optical measurements from the Fly’s Eye GLM Simulator (FEGS) instrument to intercompare with GLM at a higher resolution (~2 km x ~2 km from Fly’s Eye at nadir vs ~8 km ~8 km at nadir for GLM).