Tornado sirens: 'Cold War technology'

Tornado sirens: 'Cold War technology'

CHAMPAIGN — After a rainy Thursday filled with severe thunderstorm warnings, over 100 people packed into a Parkland College auditorium to learn how to spot tornadoes.

These volunteers play a key part of the process for emergency officials sounding tornado sirens.

"In many cases, the local spotters, they're going to be reporting into that emergency manager or maybe the fire chief that's going to make that call. It's the eye-witness type of report that's critical to that process," said Chris Miller, National Weather Service warning coordination meteorologist.

While twisters occur throughout the year, April is the beginning of tornado season.

And spotters in Illinois are kept busy.

The Land of Lincoln averages 12 tornadoes during April, up from three in March, according to the NWS' Storm Prediction Center. The state has the fifth-most tornadoes per square mile, behind Kansas, Florida, Oklahoma and Iowa.

The annual statewide tornado drill took place March 7. In Champaign County, all 84 sirens passed the test, which also included a message on TV from the NWS.

The county will conduct its regular monthly siren test again this Tuesday at 10 a.m.

While weather alerts are issued by the NWS, based on radar and spotter reports, the decision to sound a tornado siren is often a judgment call by a local emergency official.

The Champaign County Emergency Management Agency can control all the sirens in Champaign, Urbana and Savoy.

"There's a box that we have that has a key. You turn the key, and then you hit the right buttons to sound the alarm," said John Dwyer, director of the Champaign County EMA. "We have a box, as well as the 911 center."

In Thomasboro, which has three tornado sirens, storm coordinator Laurel Zook said "it can be a hard judgment call" that depends on updates from NWS and a local spotter who's a "weather fanatic."

"I'm very particular about how I do that," Zook said. "If you activate it on a whim here and there, then you've just freaked a bunch of people out for no reason. Are they going to believe you the next time?"

She's been doing this for about 14 years, so she knows what to look for.

"We watch the storm system coming in," she said. "If there's a rotating wall cloud, there's a strong possibility a tornado could drop out, so that may be something we activate for."

Also, "if there's a storm coming through Mahomet, it's probably going to catch us," Zook said. "We try to give everyone as much warning as possible. They generally don't get more than 10—15 minutes of warning anyways."

If Zook authorizes sounding the tornado siren, her dispatcher will set them off using a two-part radio-controlled system.

Emergency officials try to avoid "crying wolf," which is why Pesotum had a headache in 2013 when its tornado siren sounded for no reason.

While the village never determined what caused the false alarms — whether it was malicious or malfunctioning — the siren has been fixed.

"We had the company that we bought the sirens from do some work and reset the calibration on it that allows us to set it off," Village President Cheryl Smitley said. "It works fine now and hasn't happened since then."

Mahomet has six tornado sirens and is adding a seventh, said Gary Crowley, who operates the town's sirens.

"We're expanding to the northeast and covering an area not really covered by the sirens," he said.

The new siren will cost about $23,000 to $25,000, Crowley said.

When a tornado hit Gifford on Nov. 17, 2013, it blew down one of the town's three sirens.

Gifford replaced it for "close to $30,000," Police Chief Sean Weary said, most of which was covered by grants or insurance.

Tornado sirens in Champaign County are clustered where people are.

This means people living in rural areas between towns, such as Zook, might not be able to hear the nearest tornado siren.

"I live between Rantoul and Thomasboro," Zook said. "If we're real lucky and the wind is blowing right, we can barely hear Rantoul's."

Zook tried to get a siren installed at the mobile home park where she lives, but the cost proved to be prohibitive.

While people in the country might not be able to hear the sirens, just about every emergency official interviewed for this story pointed out without prompting that tornado sirens are outdoor warning sirens.

"You won't hear them inside your house," Mahomet's Crowley said. "If your windows are closed, you're not going to hear it unless you're right under it."

The NWS' Miller said sirens aren't necessarily the best way to learn about a potential tornado.

"There's so many ways to get information," he said. "Don't just say, 'I'm not going to go to the basement until the siren goes off.'"

He encouraged people to use a weather radio and to monitor social media. Smartphones also now automatically send alerts for tornado and flash flood warnings.

"To be honest, it's Cold War technology," Miller said about tornado sirens. "It's an important part of the process, but what people have to understand is, it's not the only part of the process."

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