Outdoor warning siren criteria now includes 70 mph winds for rural Dallas County

Allison Ullmann
Perry Chief
An outdoor warning siren in Perry.

Rural Dallas County communities will see a new activation criteria for the outdoor warning sirens as of Oct. 1.

AJ Seely, Coordinator for Dallas County Emergency Management, said Dallas County communities outside of the metro area were using tornado warnings or a spotted tornado as an activation criteria for the outdoor warning sirens. That criteria will now include 70 mile per hour or greater winds beginning on Oct. 1.

“Our intent with this change is to be more consistent with our metro partners that many of our community members are traveling to. And also with neighboring counties that also use this criteria,” Seely said.

The change only applies to communities in Dallas County that do not currently use the 70 mile per hour wind criteria. The change does not apply to the communities of West Des Moines, Waukee, Clive, Urbandale, Grimes or Granger.

“This should bring some consistency so that if someone is from Adel and driving to Waukee and they don’t have to figure out what the difference is,” Seely said. “Our goal is to increase perception to warning hopefully by having consistent warning protocols so people will understand what it means regardless of where they’re at.” 

He added that they have been considering a change in the activation criteria for around a year. A workgroup was formed that included different jurisdictions and the National Weather Service to look into updating the criteria. 

“We were worried about desensitizing the public by sounding the sirens at every storm, but when in reality only a very small amount hit the 70 mile an hour criteria,” Seely said.

He added that the workgroup found there was potential to sound the sirens one additional time per year. The decision was made to implement the additional activation criteria as of Oct. 1.

“The derecho, I think is a perfect case example of why this needs to be in place and I don’t think we want to wait any longer in the off chance that another event like this happens,” Seely said.

Seely said the National Weather Service data includes what the expected winds will be in their severe thunderstorm warning.

“If it’s 70 or greater we’ll go ahead and activate the sirens. Or alternatively, if a trained weather spotter reports that there’s 70 mile an hour winds in our community, we can also activate that way as well,” he said.

He added that the sirens will only be activated in the areas affected by the warning. Though for other storms, like the Aug. 10 derecho, Seely said the severe thunderstorm warning was published ahead of time.

“Maybe before the high winds reached that location. It may seem like the sirens are sounding too early. But there’s always the potential for more to come so we want people to go inside and seek that additional information and be in a safe place,” he said.

One of the outdoor warning sirens in Perry.

Seely added that the outdoor warning sirens are meant to warn those outside.

“The big thing we want the public to know is anytime the outdoor warning sirens go off, we just want that to be a cue to go seek further information,” he said. “Whether it’s 70 miles an hour winds or a tornado, if those sirens go off, we want you to go inside and turn on that weather radio, tune in to local media or listen to another source to know that some sort of severe weather event is imminent.”

He encourages community members to have alternative ways to receive alerts. Dallas County Emergency Management hosts its own alert platform. Seely said people can sign up for free by texting “DallasAlerts” to 69310 and a registration form will be sent to sign up.

“We want to emphasize that outdoor warning sirens are for outdoors. It’s great if you hear them inside but we don’t want you to rely on them if you’re inside,” he added. “Have another way to receive alerts. We really want people to take that extra step and that initiative and be aware of severe weather warnings prior to it being above your head.”