Decision To Turn On Tornado Sirens Not Taken Lightly

AURORA, Colo. (CBS4) - Last week the severe storms prompted several cities to activate their tornado sirens, but many people said no tornadoes were spotted. So viewers asked CBS4 to look into the reasons behind the alarms.

Severe weather is a fact of life in Colorado. It can also lead to frustration. Last Thursday a tornado siren went off in Aurora, sending Sally Garwood and her two small children running for shelter.

"I looked up in the sky and I saw no funnel clouds, no strange clouds, nothing," Garwood said.

After the family spent 30 frustrating minutes inside a recreation center the warning turned out to be false.

"The siren means there is a funnel cloud, you need to take shelter, not that there could be a funnel cloud sometime in the near future," Garwood said.

"A funnel cloud was spotted in southeast Denver," Chief Patrick Hynes with Denver fire said.

Hynes monitors the weather from the Combined Communication Center. His crew makes the call to sound the alarm in Denver.

"We ere on the side of caution. If there's any doubt, we activate the siren, but we're cognizant that we only activate when there's a real emergency," Hynes said.

Hynes said tornado sirens are only activated after consulting with the National Weather Service and several other trusted sources.

"Weather spotters or police officers and fire fighters on the streets; or multiple calls with credible information that there's an actual tornado on the ground," he said.

Hynes' counterpart in Aurora, Matt Chapman, says the decision to turn on the siren is not taken lightly. It's also not an exact science.

Despite the severe weather, tornado sirens are rarely activated after August.

Both Aurora and Denver say they typically sound their alarms less than 10 times a year.