Outdoor Warning Sirens

The City's 10 Outdoor Warning Sirens (OWS) are primarily used to warn people outside of approaching severe weather conditions. Even though the outdoor warning sirens can be loud enough to be heard inside some nearby structures, they are not intended to warn people indoors. The sirens are also used for other emergencies such as a hazardous chemical spill, which may require sheltering in place or evacuating. 

After hearing the OWS, please seek more information from local radio and television broadcasts.

When activated, each siren will produce a very loud, steady tone signal. The sound will have a natural decrease/increase due to the 360-dregree rotation of the siren head. The sirens will only be initiated in the case of severe weather directly threatening Bedford as reported by the National Weather Service, a storm spotter, or certain City employees that meets at least one of the following criteria:

• Reported hail of 1.50” in diameter or greater (or smaller for areas or events where large numbers of people are outdoors)
• Rotation in a dangerous cloud or a tornado
• Straight-line winds over 70 mph

How do the sirens work?

The outdoor warning sirens strategically located and covering each neighborhood in Bedford. They are activated electronically by radio control and can be sounded independently to alert sections of the City, as needed. There are three separate control stations at different locations to assure continuity of the system. Each siren and control location has battery emergency power and emergency power by generators.

Why didn't the City of Bedford activate its outdoor warning sirens when other cities activated their sirens?

Based on the activation criteria, each threatening situation is carefully evaluated by a team of emergency management staff using up-to-the-moment information concerning how the threat will affect the people in Bedford. 

The emergency management teams of each city have worked together developing plans and guidelines in an effort to be consistent when activating their sirens during critical public emergency events. However, there will be conditions when neighboring cities may activate their systems and be heard in Bedford and the event does not affect Bedford, which causes confusion. In most cases, all cities in our area use the siren activation guidelines listed above.  

When do we test the sirens?

The City performs a system test on the first Wednesday of each month at 1 p.m., unless there is a severe weather warning or dark overcast skies that day. The “loud test” is a full test of each siren checking all functions, which can last up to two minutes. The “growl test” performs the same assessment as the “loud test” except the siren speaker bell only makes one full rotation with sound usually lasting less than 30 seconds. Staff also tests each siren’s electronics twice daily, notifying emergency management of the results and reporting any issues.