In the wake of this weekend's deadly tornadoes in Joplin, Mo., and Minneapolis, area emergency management officials remind local residents to take cover whenever they hear weather sirens sounding.
Bill Keller, director of the Champaign County Emergency Management Agency, noted that a tornado warning was issued for Joplin about 20 minutes before the storm hit, with the sirens sounding about 17 minutes before impact.
Keller said he and his staff monitor the Doppler radar and other information from the National Weather Service, as well as reports from spotters throughout the area.
Keller said the 38 sirens in the metro Champaign-Urbana area are triggered from the Champaign County Emergency Operations Center in Urbana, with a backup location at the METCAD 911 Dispatch Center.
Keller said he also keeps in radio contact with emergency management personnel in the smaller communities around the county to help them make decisions on sounding weather sirens.
Keller said the decision on whether to sound the sirens depends on the specific warnings, the projected path of the storm and information from the storm spotters.
"The spotters are volunteers who are looking for the rotation of the storm," Keller said. "Generally, the sirens in Champaign-Urbana are sounded when there is visual confirmation of a tornado approaching the cities."
If the storm takes place at night or during a time of limited visibility, Keller said, his staff depends more on information from the National Weather Service to make a decision on sounding sirens.
Keller said people hearing a weather siren should take cover for at least 30 minutes and should monitor weather radio or local media.
If the sirens in Champaign-Urbana sound a second time, Keller said a new 30-minute period begins.
"There is no all-clear signal," Keller said.
Vermilion County Emergency Management Agency Director Ted Fisher said he and his staff depend on both the National Weather Service and local weather spotters to make a decision on sounding sirens.
Fisher said he relies more on radar reports during the night when visibility is limited. He added that the weather spotters can sometimes identify nighttime tornadoes during lighting flashes.
"We have the ability to set off nearly all of the county's sirens here at our headquarters, except for Hoopeston, which sets off their own sirens," Fisher said. "We only set the sirens off for active warnings."
Fisher said there are about 40 sirens in Vermilion County.
Fisher advises residents to take cover immediately when they hear a siren until the storm has passed.
"We don't set off an all-clear siren message because it confuses people," Fisher said.
Rantoul Emergency Services and Disaster Agency Director Danny Russell said the village sounds its sirens whenever a tornado warning that threatens the village has been issued by the National Weather Service or whenever a police officer, fire department person or a trained weather spotter sees a funnel cloud.
Russell advises people who hear the siren to take cover and remain there for 30 minutes.
"Should the danger continue, it will be repeated every 30 minutes for as long as it continues," Russell said.
Mahomet Emergency Services and Disaster Agency Director Gary Crowley said the village sounds its sirens when a local spotter sees a funnel cloud or tornado or when Doppler radar indicates there is one in the vicinity.
"We have spotters throughout the area," Crowley said. "When people hear the siren, they should take cover until the National Weather Service says it is all clear. Listen to a weather radio to determine when there is an all-clear from the weather service."
St. Joseph Emergency Management Supervisor Rusty Chism said his community depends on communication from the county Emergency Management Agency, along with storm spotters and National Weather Service information, before making a decision on whether to sound a siren.
"Just because they set them off for Champaign-Urbana doesn't necessarily mean we set ours off," Chism said. "We pay attention to what the storm spotters see. A lot of times the sirens are set off in Champaign for activity way west of here, and sometimes the activity dissipates by the time it gets to St. Joseph, so we don't set the sirens off."
Chism said all three of St. Joseph's weather sirens are sounded at the same time.
If the danger continues 30 minutes following an initial siren, Chism said a second siren would be sounded.
"But we've never had to do that," Chism said.
Here are some tips from Champaign County Emergency Management Agency Director Bill Keller on what to do when a siren sounds: