The most common and widely recognized method of warning is through the use of outdoor warning sirens. They are used by communities for a variety of purposes, including:
- Testing – 1st Wednesday of each month at 1 p.m.
- Tornado warnings and severe thunderstorm warnings with sustained winds of 70 mph or greater
- Major hazardous material spill
- Nuclear power plant incident
New outdoor warning siren policy for Dakota County
In the past, outdoor warning sirens were activated during tornado warnings and severe thunderstorm warnings, which means that the winds have reached a sustained speed of 58 mph or greater. From 2010-2014, this resulted in 96 instances where sirens were activated.
The new policy continues to activate the outdoor warning sirens during tornado warnings, but increases the sustained wind speed needed to prompt sounding the sirens during a severe thunderstorm warning. Instead of 58 mph, sirens will sound when wind speed is expected to meet or exceed 70 mph. If this policy was used over the last five years, the use of sirens would have been reduced by 75 percent.
City and county emergency managers asked the National Weather Service for this recommendation. The National Weather Service based the policy on more accurate weather forecasting and technology and wind damage information.
When sirens are sounded
During emergencies residents will hear a 3-minute steady signal of the sirens. The sound range of a siren is about one mile, depending on the surrounding terrain.
When you hear the siren and are unsure what they are sounding for, go indoors and turn your radio or TV to one of the Emergency Alert Stations (all TV stations and most radio stations in the metro region are EAS equipped) and listen for essential emergency information. Do not call local fire or police agencies to ask why the sirens are sounding. If it is an emergency, they are busy getting equipment and manpower to the emergency scene.
No “all clear” signal is issued. That is why it is important to monitor your local radio and television stations during times of emergency for further information.
When sirens are activated for severe weather
The Emergency Managers from each of Dakota County’s cities have determined the policy for sounding warning sirens. The Dakota Communications Center activates the sirens.
Sirens are activated depending on the areas of the county included in the warning issued by the National Weather Service. Warnings can be on a city-by-city basis or for the entire county. The county does not make the decision of where to activate sirens.
Activation of the sirens can also be triggered by the Dakota Communications Center when notified by local law enforcement officers or a trained network of weather spotters.
The warning sirens need to be sounded before severe weathers strikes an area because possible electrical outages during severe weather would make the sirens inoperable.
Be alerted inside your house
The siren system was not designed to be a warning device for people inside their homes—it was designed for people that are outside of their homes, away from radios or televisions, which may be broadcasting warnings.
To add additional protection while you are inside, purchase a weather alert radio. These weather alert radios can be purchased at many retail stores. Prices vary from $20–$200 depending on the model and features. If you purchase a radio with the SAME feature (Specific Area Message Encoding), the receiver is capable of turning itself on from a silent mode when the signal for your area is sent out. These radios can be programmed for specific areas, so you do not receive alerts from areas far away.
Other notification options
Local public safety has other tools that they use to alert the public. This includes the Emergency Alert Program used by the Dakota Communications Center. This mass phone notification system allows the public to register their cell phones to receive non-weather related alerts on their phones when issued by local public safety officials. Sign up for the Emergency Alert Program.