Lightning strikes are not infrequent along Evanston’s lakefront.

Something about the confluence of sailboats with metal poles and masts, flag poles on shore and swimmers standing in water seems to be conducive to attracting lightening said Tim Carter, the city’s Lakefront Director.

Tim Carter, Evanston’s Lakefront Director, stands in front of the Dempster Street Beach Office, where an upgraded lightning protection system was installed on the roof. Credit: Robert Seidenberg

He estimated staff members have to clear beaches roughly 10 times a summer in anticipation of a storm landing.

“So far I think we’re at six or seven,” he said, asked for a count during an interview on Thursday, Aug. 25.

That’s all the more reason why Carter was eager to talk about the upgrade of the lightning protection system the city has been using to alert swimmers and other lakefront users should a storm be heading their way.

The city has been using a lightning protection system along the lakefront since 2007 when a Thor Guard system was installed on the roof of the Dempster Street Beach office.

A computerized system, the Thor Guard can predict the probability of a lighting strike within eight to 20 minutes before it occurs, Carter said, and is regarded as 97% accurate.

The original system, “obviously with the time and harsh weather elements down there – the sand in particular getting into the sensors – it kind of was giving us a false reading occasionally,” he explained. “So it was definitely time to invest in a new system down there.”

So the city, upgraded to a new model for $6,000 and the new sensor is 100% enclosed from the effects of water, sand and the other elements, Carter said.

Plus, it has “a horn strobe on the exterior of the beach house,” he said.

Now, whenever there is potential for a lightning strike in the area, a strobe light will turn on and a warning horn will sound with an uninterrupted 15-second blast, Carter said. The flashing light continues until it’s all clear.

“Previously, before the upgrade, it would just be a little blinking light inside the lifeguard room, and then our lifeguards would radio all the beaches,” Carter said.

He further noted that, although city beaches are only staffed Memorial Day through Labor Day, “this system is active through November.”

Therefore, “Whether you’re taking a jog in the park or just enjoying a late September day on the beach, if you hear that siren, then you know it’s not safe; it’s time to come off,” he said.

“And then, if there’s an all-clear as well, it’ll do three-, four- or five-second blasts to be heard up to 600 yards from the beach offices.”

The horns are pointed toward the beaches, parallel to the lake, so not to disrupt homeowners greatly, he said.

They are also positioned so vessels off shore, “which is our paddle boarders, our kayakers, sail boat captains, can hear that horn,” Carter said. “So it’s just another technology we are using to keep our resident safe on the lake.”

Bob Seidenberg

Bob Seidenberg is an award-winning reporter covering issues in Evanston for more than 30 years. He is a graduate of the Northwestern University Medill School of Journalism.

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  1. It would be nice if the device would not only give a warning, but an all-clear, once the static level has dropped. We used to have to wait 30 minutes after the last detection of actual lightning within 10 miles, to return to the water. It seems like this device could have a “red light” and “green light”, if it’s constantly measuring static (?).

  2. There was a really interesting lawsuit in federal court (it’s on PACER) regarding the Thor Guard systems and the performance of their old models versus the new models. City should make sure they have the ability to test these new sensors before they go into production!

    1. The city certainly got their test yesterday! I swear lightning was hitting trees and buildings all around me.