Additional Weather Warning Type Will Activate City Sirens, Alerts
Published on April 02, 2025
Beginning this spring, the City of Sioux Falls will include an additional severe weather type, “destructive severe thunderstorm warnings,” for outdoor siren activation. This warning category aligns with the protocols already in place for tornado warnings, which include outdoor warning siren activation and a Wireless Emergency Alert (WEA) sent to cell phones and other mobile devices in the impacted area.
“The public’s action remains the same: If you hear the outdoor warning sirens or receive a WEA to your cell phone, take shelter immediately and stay there until the threat has passed,” said Regan Smith, the City’s Emergency Manager. “The public does not need to do anything differently with the addition of this storm category. The best thing they can do, and this applies every year, is to be weather aware and have a plan for what you will do when severe weather arrives.”
“Destructive” is a category for thunderstorms that have 80 mph winds or greater and/or at least 2.75-inch diameter (baseball size) hail, according to the National Weather Service (NWS). These storms are considered life-threatening and may cause substantial damage to property. “Destructive” is the highest of three categories recently added by the NWS to thunderstorms to differentiate their severity. When a destructive severe thunderstorm warning is issued, the WEA will be sent and the outdoor sirens will be activated by the City of Sioux Falls, the same as the current system for tornado warnings.
“The addition of this weather type does not mean your phone is going to be buzzing constantly with alerts,” Smith said. “These destructive thunderstorms are rare but are as dangerous as tornados, which is why the NWS determined they warrant an outdoor siren activation and WEA.”
Outdoor Warning Siren System
The City’s Emergency Management team, which is a division of Sioux Falls Fire Rescue (SFFR), maintains and operates an extensive system of outdoor warning sirens. The system is designed to be an early warning device primarily for people who are outside and away from an information device, like their phone, television, and/or radio. The sirens are tested at 11 a.m. every first Friday of the month from March to October.
Outdoor warning sirens are not intended to be heard indoors. Multiple factors, like the hum of air conditioners, background noise, or thunder, rain, and wind, all contribute to outdoor warning sirens being difficult to hear while inside.
Specifically for people indoors or with access to communication devices, emergency management and NWS officials rely on WEAs and local media to alert the public to incoming severe weather. Additionally, emergency management officials recommend using a programmable National Oceanic and Atmospheric Administration (NOAA) weather radio.
Wireless Emergency Alerts (WEAs)
The Wireless Emergency Alerts system is an essential part of the nation’s emergency preparedness and response. WEAs are used across the United States by government agencies to alert the public to critical situations, like dangerous weather, missing children, or other hazards. Messages are sent to compatible cell phones and other mobile devices within a targeted geographic area. WEAs will appear automatically on devices within the area; however, cell phone users can opt out of certain types of notifications in their phone settings. Residents should check the settings on their cell phone to ensure they can receive WEA messages.
The City of Sioux Falls also maintains a “City Emergency Alerts” tool that allows residents to sign up for other weather alerts, like watches and warnings. Participation in these notifications is optional, and categories can be found at siouxfalls.gov/alert. For additional information about the City’s emergency management program, visit siouxfalls.gov/emergencymanagement.
The annual community tornado drill will be held Wednesday, April 9, 2025, at 10:15 a.m. Residents, schools, and businesses are encouraged to participate and practice their severe weather plans. The outdoor warning siren system will be activated during the drill. The drill is part of South Dakota Severe Weather Awareness Week, which is April 7 to 11.