If you've been in North Texas during severe weather, chances are you've heard the loud signal set off by outdoor warning sirens. But even long-time residents sometimes wonder, "Why are these sirens going off?" if there isn't a tornado headed right for the area.
Emergency sirens are designed to be signals for people outdoors to find shelter. The cities that run each siren system make the decision to set off a warning based on different factors.
In Fort Worth, in order for sirens to be sounded, winds must reach 60 mph, hail must be larger than an inch in diameter or a tornado must either already be on the ground or about to touch down, according to Juan Ortiz, the city's emergency management coordinator.
Other cities have different guidelines for issuing a warning.
Ortiz said the point of the outdoor warning system is to get those outdoors in the most imminent danger the knowledge that they need to go inside and get information.
"It's a constant battle that we make sure we sound the right sirens, at the right time, to maximize the intent to allow folks to come indoors and find out what's going on," he said.
Fort Worth's siren system allows sirens in specific areas to be sounded, based on forecasts for where severe weather will hit. But warning systems in other cities may set off sirens on the whole system even if the danger is limited to a specific area.
Cities also may use other systems to get out information about severe weather, including reverse 911 calls, TV or radio broadcast interruptions, text messaging, and social media.
NBC 5 is committed to keeping North Texans safe during severe weather events and may interrupt programming to bring the latest information to the area.
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