Following a tornado that touched down in southeast Round Rock and caused extensive damage on March 21, residents called on the city to install tornado sirens, pointing out that neighboring cities Georgetown and Jarrell have long used them as an additional safety measure.

Williamson County figures state in Round Rock alone, several dozen businesses, roughly 680 homes and numerous vehicles were either damaged or completely destroyed by the March tornado that took a northeastern path for several miles, causing roughly $32 million in damage.

However, Round Rock Fire Chief Shane Glaiser said a siren would not have served as an adequate warning in this case, as the tornado touched down in the city before a warning was even issued by the National Weather Service.

“They’re not as effective as one may think,” Glaiser said.

Tornado sirens are activated by emergency response staff once a warning is issued, Glaiser said, adding that they also often require someone to be outdoors to hear them.

“Think about a lightning detector at a baseball field. It’ll pick up the static 20 miles away,” Glaiser said. “It’ll set off a warning to tell the baseball team to go indoors and shelter. The same happens with the tornado siren—it’s just a warning device.”

Other warning systems, such as push notifications from weather monitoring apps, robocalls from local government, local news stations and weather radios are better at warning residents, Glaiser said.

For example, even in areas where there are storm sirens, they are not useful for those already inside their homes, including Glaiser’s in-laws who live in Georgetown.

“They live about a block away from one of the tornado sirens, and I was there during the major thunderstorm,” Glaiser said. “They’re in an older house built in the ‘70s, so it doesn’t have near the insulation and soundproofing that today’s homes have. I barely heard the siren.”

Capital Area Council of Governments, or CAPCOG, director of Homeland Security Martin Ritchey said his agency operates a regional notification system that uses telecommunications devices and geolocation to warn those in the area of potential extreme weather events. Automatic alerts, similar to Amber Alerts that inform people of child abductions via their cell phones, also warn those in a given area of extreme weather.

“This type of alert is not tied to your address, but to the actual location of a phone. This allows people traveling through a warned area to receive messages along with residents,” Ritchey said.

Local jurisdictions, Ritchey said, can activate the CAPCOG alert system at their discretion. However, like outdoor tornado sirens, they require a person to activate them.

National Oceanic and Atmospheric Administration data shows Round Rock’s history of tornadoes is sparse—before the March storm, the last tornado to touch down in the city was in 2004, 18 years ago. Glaiser said the infrequency of tornadoes in the city, combined with the fact that they are not effective as a widespread warning, is why the city has not installed sirens.

In addition to purchasing weather radios and creating a weather preparedness kit, the National Weather Service recommends families create a communication plan. The NWS suggests establishing possible shelter locations and a meeting place in case family members are separated during a storm.