The GOES-16 Geostationary Lightning Mapper: Using Lightning Trends Operationally during Tornadic Storms in VORTEX-SE and Other Cases

The vast coverage and high spatiotemporal resolution of the new Geostationary Lightning Mapper (GLM) spans a wide array of applications from research and forecasting to health and safety. Ground-based Lightning Mapping Arrays (LMAs) have already been used to observe lightning trends, with operational concepts integrated into Hazardous Weather Testbed and GOES-R Proving Ground trials as a proxy for the GLM to determine the relevance of flash detection as an addition to traditional radar-based warning algorithms. Many visualization methods, from point data to gridding, were tested; combinations like gridded Flash Extent Density (FED) and other flash moments such as average flash area, were found most useful for safety operations, and still others may prove just as crucial for monitoring storm trends. This study has a twofold aim: first, to determine how to best use and visualize the actual the GLM data for a variety of scenarios in the warning decision process to maximize its advantages while building on our current experience; second, to continue the established investigation of lightning trends with severe weather.

To further research on severe weather lightning trends, a variety of cases from 2017 and 2018 will be examined using the GLM and other LMA data, including from VORTEX-SE. Substantial exploration has already been done on the use of lightning trends with supercells; here, QLCS circulations will be studied due in part to their substantially different driving mechanisms and kinematic environments, which are expected to carry significant impacts on mixed-phase region depth and thus lightning output. Because relatively few of such studies exist, the utility of flash rates in specifically QLCSs will be examined here. To understand how the GLM can be best used operationally to monitor these convective systems, the performance of all 7 flash moments will be studied in detail, through various display methods and time aggregations.