Sirens are used by the National Weather Service to alert people who may be outdoors of a threat of severe weather. When a tornado siren is heard it means that a tornado has been spotted or is strongly indicated on radar.
The sirens have an effective range of about a mile from the horn location. However, the sound is affected by hills and buildings and high background noise levels.
During severe storms, the horns are sounded to warn residents of the impending danger. The sirens can also be sounded during a tornado warning or other emergency to help alert residents.
When a siren is sounded it will usually only be for three minutes. The siren will then automatically turn off to preserve battery power.
If you hear a siren, seek shelter immediately. Go indoors and listen to radio or television for additional information.
It is important to know that outdoor warning sirens are not a substitute for watching the weather or getting other forms of weather alerts. You should also always have a NOAA weather radio to be alerted if you are inside your home or car during a severe storm.
Douglas County has approximately 120 outdoor warning sirens installed and operational. The sirens are diagnostically and audibly tested monthly. The testing is performed on the first Wednesday of every month, unless inclement weather conditions prevent testing.
