Outdoor Warning Systems

St. Charles County maintains a network of Outdoor Warning Devices (OWDs), otherwise known as Tornado Sirens, primarily in unincorporated St. Charles County. Presently, EMD maintains 29 Whelen WPS-2800 OWDs and one Federal Thunderbeam mechanical siren. County OWDs, as well as municipal OWDs owned by Wentzville and O'Fallon are capable of voice announcements, too. Wentzville, O'Fallon and St. Charles (City) participate with St. Charles County in a joint warning points program.

The cities of St. Peters and Lake St. Louis own and maintain their own system of OWDs. St. Charles County cannot directly activate these OWDs, but maintains a radio network that allow these cities to alert other warning points downstream.

Presently, there are a total of 74 Outdoor Warning Devices in St. Charles County. Here's a list of devices used, their locations and the manufacturer's rated specs. Please note some OWDs, particularly older mechanical units, rely on AC power and cannot be battery backed-up. Newer OWDs in both the County and municipalities are supplied with battery back-up. We are now spec'ing Solar Power for County owned OWDs! Solar power allows us to get OWDs into operation immediately once they are installed. It also makes OWDs immune to power outages. So far, solar power devices have demonstrated they are lower maintenance with a greater mean time between failure, saving both time and money while providing greater protection by not relying on the power grid to recharge the batteries.

EMD tests OWDs on the First Monday of the month at 9 AM. If that falls on a holiday, the OWDs are tested on the first Tuesday at 9 AM. Tests are not conducted during inclement, threatening or impending hazardous weather.

Please report any OWD that does not activate or that has trouble to: 636-949-3031.

What should you do when you hear an OWD or Tornado Siren?

• SEEK SHELTER IMMEDIATELY!
  
• Tune to KMOX 1120 kHz AM, National Weather Service 162.55 MHz, Cable TV or your local TV News for official information.
  
• DO NOT call 9-1-1 unless you have an EMERGENCY to report. Official information WILL NOT be provided by the 9-1-1 Telecommunicator.
  
• NEVER see if you can play "spot the tornado!"
  
• NEVER stay outside to try to hear the siren better!
  
• St. Charles County DOES NOT broadcast an "All Clear" signal. It's important to stay tuned to official information to know when it is safe to come out.

OWDs and tornado sirens can be sounded for other emergencies that you must be aware of. These may include a hazardous materials incident which may require you to stay in your home. It is important to keep a portable radio with fresh batteries ready to go so you can receive information and protect yourself appropriately!

If you do not have an OWD in your area, you can still be safe! A NOAA Weather Radio with SAME technology can be purchased from many sources and costs about as much as a smoke detector. No home should be without one!

St. Charles County places OWDs in Unincorporated St. Charles County with consideration for areas of population over 500 and near facilities such as schools or parks. Municipalities are responsible for providing coverage within their areas. Presently, St. Charles County constructs three to five OWDs per year, as budget constraints permit. Outdoor warning devices are intended to warn those who are outside when they are sounded. They are not intended to penetrate inside a structure, especially considering ambient noise and insulation. Please augment your safety by purchasing a Weather Alert receiver! Every household should have a weather alert receiver!

Are YOU a DEVELOPER? Are YOU creating a SUBDIVISION? Don't wait for protection to get around to your neighborhood, place your own OWD in your subdivision and let safety be a selling point! Call 636-949-3031 for complete specifications on what you need to buy and install.