The Geostationary Lightning Mapper on board GOES-17, like the flown on NOAA's GOES East, is transmitting data never previously available to forecasters. The mapper observes lightning in the Western Hemisphere, giving forecasters an indication of when a storm is forming, intensifying and becoming more dangerous. Rapid increases of lightning are a signal that a storm may strengthen quickly and could produce severe weather.
During heavy rain, GLM data can show when thunderstorms are stalled or if they are gathering strength. When combined with radar and other satellite data, GLM data will help forecasters anticipate severe weather and issue flood and flash flood warnings sooner.
Also, 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 ground presents a public safety hazard. In dry areas, especially in the western United States, information from the instrument will help forecasters, and ultimately firefighters, identify areas prone to wildfires sparked by lightning.
Data from GLM will serve an essential role in helping to keep American lives and property safe when GOES-17 is in place in its operational GOES West position, where it will cover a vast swath of the data-sparse Pacific Ocean and monitor high-risk wildfire-prone areas in the western U.S.