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Earth from Orbit: When Lightning Strikes

August 18, 2022

Lightning is a major public safety threat. It can strike at any time, but it is most common in the summer months. Lightning kills about 20 people each year in the United States and hundreds more are injured

Recent severe thunderstorm activity has highlighted the dangers associated with lightning strikes. In the span of less than a week in early August, lightning led to several injuries and fatalities.

On Aug. 2, a Boston man was killed by lightning while on a backpacking trip in Wyoming, while another man was injured in the same incident. Three people died and another was critically injured as a result of a lightning strike on Aug. 4 in Lafayette Square, the public park next to the White House in Washington D.C. On Aug. 6, lightning sparked a large fire among oil storage tanks in the Cuban city of Matanzas, leading to multiple deaths and more than 100 injuries. 

NOAA’s GOES-16 (GOES-East) and GOES-17(GOES-West) satellites carry a Geostationary Lightning Mapper (GLM), which detects and maps total lightning — in-cloud, cloud-to-cloud, and cloud-to-ground — continuously over the Americas and adjacent ocean regions. GLM is the first instrument of its kind in geostationary orbit and has revolutionized lightning detection.

Lightning is a significant threat to life and property, and particularly hazardous for those working outdoors and participating in recreational activities. GLM data provides awareness of local lightning conditions and promotes better lightning safety decisions, leading to fewer lightning-related injuries and deaths. In large, long-lived storm systems, lightning may travel hundreds of miles before striking the ground. GLM can show forecasters areas far from the main line of storms where the risk of lightning strikes to the ground presents a public safety hazard. GLM data are also freely available, providing broad access to lightning information, helping people make more informed safety decisions.

GLM can not only detect current lightning activity, but its data, along with data from the GOES-16 and GOES-17 Advanced Baseline Imager (ABI), can also help predict the occurrence of lightning in the future. Scientists are using artificial intelligence (AI) to predict where GLM will observe lightning. To accomplish this, a sophisticated machine-learning algorithm was trained, using GLM data, to recognize complex patterns in ABI imagery that often precede lightning activity.

This AI model, called ProbSevere LightningCast, predicts where lightning is most likely to occur even before precipitation forms. It also indicates where lightning remains a threat in storms with intermittent lightning activity and helps determine when the threat from lightning is diminishing. The AI tool can accurately predict lightning up to 60 minutes before the first observation of lightning flashes. Clear predictive signals often emerge before rain forms, ahead of weather radar signals.

During the last few months, LightningCast was evaluated in real-time by National Weather Service (NWS) forecasters within several NOAA testbeds. Forecasters gave very favorable feedback, saying LightningCast often provides actionable lead time to lightning initiation ("first strike"), aids in NWS impact-based decision support services to partners, and provides situational awareness for nowcasting thunderstorms. Numerous NWS forecast offices are currently using the experimental LightningCast guidance routinely during forecasting operations.

LightningCast was also used by the NWS in Birmingham, Alabama, during the World Games this July to aid in decision support to the games' organizers, who postponed several events due to lightning. 

The advanced data provided by GOES-16 and GOES-17 allow for new and innovative applications. Not only is the satellite data useful for depicting current weather conditions and aiding in warnings, but it is also critical for predicting hazardous conditions in the future. The LightningCast tool demonstrates a new way to use satellite data to help keep us informed and stay safe.

As thunderstorms occur with a threat of lightning, NOAA satellites work with partners and decision-makers to keep the public safe and informed.