Lightning Detection System

On average, Florida has 3,500 cloud to ground lightning flashes per day and 1.2 million flashes per year according to

Because of this electric weather, Stetson University has installed a lightning warning system designed to alert anyone outside on the campus grounds to the presence of weather that can produce lightning.

According to Thor Guard, the company that manufactures the system, every thunderstorm produces a unique “electrical footprint” at the surface where lightning is most likely to occur. The extent or shape of this electrical footprint depends on many factors: season, pressure, wind speed, temperature, elevation, and others. Given that all of these factors can change in just seconds, the electrical footprint also changes to reflect the favorable locations for lightning to strike.

When the Thor Guard equipment detects an electrical footprint with a 98 percent probability for a lightning strike within a 2.5-mile radius of campus, it will automatically send a 15-second audible alert through sirens installed at the Public Safety building, the scoreboard at the Athletic Training Center, the cupola on top of Elizabeth Hall and the pool at the Hollis Center.

The sound is the same as what you would hear on a golf course when bad weather approaches. If you are outdoors and you hear the sirens you should move indoors immediately. Once conditions return to a safe level, the system automatically signals an all clear alert – three five-second siren blasts.

Students, faculty and staff are encouraged to seek shelter if they hear the sirens alerting them to the probability of a lightning strike in the area. Also, continue to use good judgment and seek shelter if storm conditions appear to be close to the university, whether or not you hear the siren.