By Adrienne Fawcett
A lot of people heard warning sirens on Monday night and scrambled to their basements. And then, a lot of people heard warning sirens, paused to wonder … and went back to whatever they were doing. What did you hear and do?
In Lake Bluff, tornado warning sirens started blaring at about 10:55 p.m. In Lake Forest, there were no tornado warning sirens.
Deputy Chief David Belmonte of the LBPD said the National Weather Service issued a tornado warning for Lake County and reported that Doppler radar indicated a severe thunderstorm capable of producing tornadoes approaching Wauconda and moving east.
Lake Forest didn’t activate its tornado sirens because authorities didn’t feel the criteria was met in their community, said LFPD Deputy Chief Glenn Burmeister. But don’t think you’re going nuts if you heard a siren in Lake Forest Monday night—you did, just not for a tornado. What you heard were lightning strike alerts, which go off automatically at the golf course and parks when lightening is in the area, said Deputy Chief Burmeister. (On Monday this was at about 10 p.m.) Â He said the lightening sirens are not as loud as the tornado siren and are of shorter and more frequent duration.
LBPD Deputy Chief Belmonte said police activated the sirens after closely monitoring the storm along with the County’s Emergency Management team.
“At about 10:45 p.m., officers reported observing rotation in the storm clouds, which was verified by the National Weather Service near Libertyville. The storm was reported to have exhibited some weak rotation, and tornadoes could develop quickly. Although the Weather Service stated one was not immediately likely, they encouraged people to move to a place of safety inside a basement or small interior room. At this time, the determination was made to activate the siren as a precaution. Areas north of Lake Bluff, which were also in the storm path, also activated their sirens. Although a tornado never actually touched-down in the area, conditions were favorable for one to develop.”
How do you distinguish whether a warning siren is for a tornado or, God forbid, something else–such as a terrorist attack? In Lake Bluff, the siren sound for weather warnings is a steady tone. If there is a hazard such as a terrorist attack, the alert tone will be a start/stop tone for several minutes. An all clear is three short bursts of the siren.
In Lake Forest, sirens that are used for tornado warnings also have voice capacity, so the potential is there for other uses should the need arise, said LFPD Deputy Chief Burmeister.


