Martin County Emergency Management Agency, the St. Lucie County Department of Public Safety and Florida Power & Light will conduct quarterly testing of the outdoor warning sirens for the St. Lucie Nuclear Power Plant at noon, Thursday, December 1.
Each of the sirens in Martin County will sound for one minute at noon. Before and after the sirens sound, a message will be broadcast on the sirens' public address system stating, "This is only a test." This will be done to all 91 sirens at the same time.
The siren system is regularly tested to improve public awareness of its function and ensure its operability.
Original source can be found here.