Metro usually tests Tornado Warning System the first Saturday of each month
The Nashville Office of Emergency Management has cancelled a regularly scheduled test of the Metro Tornado Warning System originally scheduled for March 7, 2020 at noon.
OEM tests the Tornado Warning System on the first Saturday of every month at noon as long as the weather is clear.
The current Tornado Warning System is designed to alert people in outdoor areas. The system’s goal is to make the public aware that a tornado warning has been issued for any portion of the county.
The current tornado warning system will sound tornado sirens for a period of three minutes then stop for seven minutes before repeating for another 3 minutes and stopping for another seven minutes until the command to stop the system is received by the warning system.
Metro is in the process of upgrading the current Tornado Warning System from an all-call format to a polygonal-alerting system.
The current all-call format sets off ALL tornado sirens when The National Weather Service issues a tornado warning anywhere in Davidson County.
The upgraded polygonal alerting system will automatically activate only the sirens located inside the NWS designated area with an active tornado warning instead of all sirens countywide.
The sirens will be automatically activated when the NWS issues a tornado warning.
During the upgrade process OEM will continue to set off ALL siren sites throughout the county for tornado warnings.
After all existing sites are updated, twenty (20) new sirens will be added to the system to expand the coverage footprint into more rural areas of Davidson County. The additional siren sites will bring the total number to 113 tornado warning sirens countywide.
The new Polygonal Tornado Warning System has an estimated completion date in early 2020, depending on weather.
Please note software upgrades will also play a role in the completion of the project.
Background on Tornado Warning System Upgrade
The upgraded Polygonal Alerting Tornado Siren System is estimated to cost $2 Million and was funded by Metro Government in the current 4% budget.
Metro first installed Tornado Warning Sirens in 2003. At that time, weather warnings issued by the National Weather Service (NWS) were for an entire county. Weather forecasting technology has improved significantly since 2003.
Weather warnings are now issued to potentially impacted areas based on the observed track and speed of the storms, without regard to political or geographic boundaries.
These polygonal alerts are defined by boxes drawn on a map and should be familiar to everyone as the odd shapes shown on the radar screen during television weather warning broadcasts.
The alerts will be immediate, and sirens will activate mere seconds after a warning has been issued by the NWS
Background on Current Tornado Warning System
Metro’s Tornado Warning System began with a federal grant in 2002. Between late February 2013 and the end of April 2013, 20 new sites were added, going from 73 to 93 locations countywide. Each siren is in public gathering places selected by city planners on the basis of outdoor population and population density.
The expansion was the result of a $2 million local capital improvement project recommended by Mayor Karl Dean and approved by the Metro Council. The entire system was also upgraded with new siren equipment that emit an easier-to-hear warning signal, which is more like an old air-raid warning rather than the mechanical tone previously used. The expanded, upgraded system makes the coverage area bigger and broader across Davidson County.
When the sirens are activated:
- Go inside and seek additional information on the weather via weather radio, local news etc.
- If you're in the path of the storm, go inside a sturdy building to the lowest level, away from exterior walls Stay away from windows.
- Cover your head
- If there is no building available, and the storm is on top of you, find a ditch or low-lying area
- Lay down and cover your head
- Wait until the storm passes, then go safely