Cloud-to-Ground Lightning Warning Performance of a Lightning Prediction System

Improvements to lightning warnings have contributed to decreases in lightning casualties in the United States. Lightning warnings for an area of concern are typically triggered when nearby lightning is detected by a lightning detection system, when the atmospheric electric field strength reaches a predetermined threshold, when lightning is seen or thunder is heard, or by some combination of these techniques. One manufacturer of lightning warning systems (LWS) promotes the ability to predict lightning before it occurs and users of the LWS boast of its 98% accuracy when sharing details about it on their websites. According to the LWS manufacturer, there are more than 4,000 systems in the field, with users including National Football League teams, the United States Department of Defense, the United States Tennis Association, the United States Golf Association, as well as numerous public schools, universities, and municipal parks departments.

Effective LWS are accurate (correctly warn of lightning danger) and operationally efficient (minimize downtime). Here, we review lightning warnings issued between January 20, 2021, and December 31, 2024, by a lightning prediction system located at a municipal sports facility in eastern Florida. Using cloud-to-ground lightning data from the National Lightning Detection Network within 2.5 miles of the LWS location as validation, more than 700 lightning warnings were reviewed to analyze the warning performance of the system. The performance of the LWS varied significantly from year to year, including the number of alerts, false alarms, and missed events. Overall, the system showed a high Probability of Detection and False Alarm Rate and a correspondingly low Critical Success Index.