Why did sirens go off in multiple Chicago suburbs with no tornado warnings issued? Here’s the reason

Sirens sounded in multiple Chicago suburbs during Thursday’s storms, in some cases multiple times, despite no tornado warnings listed in that area. So why did they go off and was it intentional?

While there was at least one tornado warning issued by the National Weather Service Thursday evening, many of the towns reporting unexpected sirens were not in that location.

Footage showed sirens going off in Barrington, Elgin and other locations, in some cases the sirens sounded numerous times in the same suburbs.

There were, however, several severe thunderstorm warnings in place across the Chicago area.

So what happened?

According to the NBC 5 Storm Team, while tornado sirens are traditionally sounded during an active tornado warning, or because a tornado is on the ground or rotation has been detected, some locations will sound sirens over the threat of a tornado as well.

Several of the thunderstorm alerts issued Thursday, including ones in McHenry, Kane and DeKalb counties, were considered capable of producing tornadoes.

That means that while the signs of a tornado weren’t strong enough to issue a warning, there was a possibility that the storms could spin up a tornado — and that shift could happen quickly.

So the sirens were sounded to alert residents to the possibility of a tornado, but not an active formation.

While Thursday’s storm threat has ended, another round of potentially severe weather is expected again Friday.