Now known by most as "tornado sirens" these sirens were originally used during World War II to warn of a possible air attack. As such, you may still here them called "air raid sirens" from time to time. These days, they are used to alert the public of a tornado warning.
Tornado Watch vs. Tornado Warning
The tornado sirens will not sound in the event of a tornado watch. A tornado watch simply means that the conditions are right for a tornado to develop. A tornado warning, on the other hand, means that a tornado has actually been spotted by a weather spotter or on a radar.
What To Do When You Hear the Siren
The safest thing to do if you hear a tornado siren is to take cover in a basement or windowless room or closet in the center of your house. That having been said, most of us first tune in to a local news channel to find out exactly what is going on. These days, weather equipment is so sophisticated that they can track storms and tornadoes to specific neighborhoods. This lets you know if you need to take cover where you are.
There are more than 150 tornado sirens positioned across Shelby County. They are usually mounted on top of school and fire stations. A complete list can be found at the Memphis and Shelby County Emergency Management Agency's website/
All sirens are scheduled to be tested weekly. If inclement weather occurs during the scheduled testing time, the test will not be performed. In Memphis, Millington, Arlington, Lakeland, and unincorporated Shelby County, testing is performed each Wednesday at 3:30 p.m. In Collierville, Germantown, and Bartlett, testing is performed each Saturday at noon.