A long-awaited upgrade to Nashville’s tornado warning system has been completed. Emergency managers said Wednesday they’d added 20 additional sirens in rural areas, as well as upgrading 93 existing alarms (read list of locations or view map below).
The new system allows Metro to be more geographically targeted in its alerts.
Previously, any tornado warning touching a portion of Davidson County would sound sirens countywide. The updated capability, known as “polygon” alerts, allow meteorologists to draw specific shapes where storms are expected, and the city system can allow only the relevant sirens to sound. The method is already widely used by the National Weather Service, as well as broadcast meteorologists.
The old “all-call” method drew complaints that warnings were too common and not useful.
The upgrade cost Metro $2.1 million. It was ranked as the No. 1 capital improvement priority last year by the Metro Council.
Nashville’s Office of Emergency Management says monthly siren tests will continue at noon on the first Saturday of each month, although other brief “growl” tests will end.
Metro’s warning system dates to 2003.