ST. LOUIS — When severe weather, outdoor warning sirens are one way of alerting people of impending danger.
The National Weather Service said on its website that hearing an outdoor siren boils down to one thing: "In short, it means that something life-threatening is happening and you should go indoors and get more information."
Here's what to do if you hear an outdoor warning siren.
Outdoor sirens in the bi-state are usually sounded for tornadoes, though NWS announced in 2021 that sirens will also sound alongside wireless emergency alerts when "Destructive Thunderstorm Warnings" are issued.
If you hear a tornado siren, the first step is to take shelter in a safe location indoors and tune into local media or NOAA weather radio for more information.
A tornado warning means a tornado has been sighted or indicated on weather radar and you should take shelter immediately. A tornado watch means tornadoes are possible and you should keep an eye on weather coverage and be prepared to act quickly.
The NWS has specific instructions for how to take shelter depending on where you are when a tornado warning is issued:
- At Your House: If you are in a tornado warning, go to your basement, safe room, or an interior room away from windows. Don't forget pets if time allows.
- At Your Workplace or School: Follow your tornado drill and proceed to your tornado shelter location quickly and calmly. Stay away from windows and do not go to large open rooms such as cafeterias, gymnasiums, or auditoriums.
- Outside: Seek shelter inside a sturdy building immediately if a tornado is approaching. Sheds and storage facilities are not safe. Neither is a mobile home or tent. If you have time, get to a safe building.
- In a vehicle: Being in a vehicle during a tornado is not safe. The best course of action is to drive to the closest shelter. If you are unable to make it to a safe shelter, either get down in your car and cover your head or abandon your car and seek shelter in a low-lying area such as a ditch or ravine.
Keep in mind that sirens are meant as outdoor warning systems and you shouldn't rely on hearing them from inside your home or work. For indoor alerts, the National Weather Service recommends every home and business have a NOAA Weather Radio. The Missouri State Emergency Management Agency recommends people have multiple ways of receiving weather alerts in case one fails or weather strikes overnight.
It's also a good idea to know when your local jurisdictions test their sirens. In St. Louis City and County, sirens are tested every first Monday of the month at 11 a.m. unless there is inclement weather.
More information on inclement weather safety can be found on NWS' website.