March 11, 2026
VIROQUA Wis. – Vernon County Emergency Management is changing how and when it activates local outdoor warning sirens during severe weather.
Emergency Management Director Brandon Larson announced in a press release Wednesday that the county will now trigger the sirens if the National Weather Service issues a specific high tier severe thunderstorm warning.
“Vernon County Emergency Management announces that the outdoor warning sirens will now be activated when the National Weather Service issues a severe thunderstorm warning with a destructive tag,” said Larson. “This change reflects updates to the National Weather Service warning criteria and will help keep the public safe.”
The destructive tag is reserved for the most extreme storms that pose an immediate threat to life and property. Larson explained the exact wind and hail speeds required to meet this new threshold.
“According to the National Weather Service the criteria for a destructive damage threat are at least 2.75 inch diameter baseball sized hail and or 80 mph thunderstorm winds,” said Larson.
The National Weather Service updated its thunderstorm warnings several years ago to include damage threat categories. The baseline warning is for 60 mph winds and quarter sized hail while a considerable tag indicates 70 mph winds and golf ball sized hail. Only the highest destructive category will trigger the county sirens and automatically activate Wireless Emergency Alerts on mobile phones.
Larson reminded residents that the physical alarms are strictly meant to warn people who are outside to seek shelter and gather more information.
“Outdoor warning sirens are intended to alert people who are outdoors to go inside to a safe location and seek more information,” said Larson. “If you hear a siren head to your shelter and check local news social media Everbridge Mass Notification alerts or your NOAA Weather Radio.”
The new severe thunderstorm criteria will not replace the existing emergency protocols already established across the county municipalities.
“This new activation criteria is in addition to the current processes and protocols in place for outdoor warning sirens which include tornado warnings confirmed tornado sightings straight line winds or other situations that fire departments or law enforcement deem necessary,” said Larson.
The updated siren policy comes as the county continues to refine its digital public alert system known as Everbridge. Vernon County transitioned to the Everbridge platform last summer to provide residents with precise geo fenced text messages emails and phone calls during emergencies.
Larson noted during a recent local emergency planning meeting that the system automatically rebroadcasts urgent weather alerts but is carefully managed to avoid sending unnecessary overnight notifications.
“The only thing that is going to go out between 11 p.m. and 7 a.m. are severe thunderstorm warning tornado warning and flash flood warning,” said Larson. “I do not want to send a winter storm watch out at three o’clock in the morning.”
As the spring severe weather season approaches Larson urged residents to have multiple ways to receive warnings and to take immediate action when the alarms sound.
“Ensure that you have a reliable means of receiving weather alerts to stay up to date,” said Larson. “Please heed all warnings and take necessary actions to protect yourself and your loved ones.”
Add comment