Development and Evaluation of the GLM Stoplight Product for Lightning Safety

The launch of the Geostationary Lightning Mapper (GLM) aboard Geostationary Operational Environmental Satellite-R/S (GOES-16/17), provides new opportunities to support lightning safety, such as the 30-min hazard (“stoplight”) safety product developed by the National Aeronautics and Space Administration’s Short-term Prediction Research and Transition Center. This product plots the spatial extent where lightning occurred over the past 30 min and color codes the data in 10-min bins. Using GLM’s mapping of the spatial footprint of individual flashes, the product identifies when temporal rules for lightning safety have been met based on the needs of decision-support partners [commercial airlines, 10 min; United States Air Force (USAF) 45th Weather Squadron, 20 min; emergency management (EMA)/National Weather Service (NWS), 30 min]. The effort was guided by EMA partners requesting a product that quickly shows the location and age of lightning observations in an easy-to-interpret visualization. Analysis of lightning safety rules of thumb were performed in the framework of the GLM stoplight product to determine the number of times each of the partner criteria would be violated using an Eulerian-based approach simulating an integrated decision support point of view. The temporal criteria for commercial airlines, USAF, and EMA/NWS were violated 9.5%, 3.5%, and 1.4% of the time within this sample, respectively. Examples are provided to show the GLM 30-min hazard product in linear convection, multicellular convection, and electrified snowfall events. Illustrations also demonstrate how this GLM safety product and ground-based, lightning-location systems can work in tandem to maximize lightning safety protocols.