From the NWS:
202 PM CDT
…Funnel Clouds Possible Across Northern Illinois This Afternoon…
Atmospheric conditions are favorable for the development of funnel
clouds. These funnel clouds normally only protrude a few hundred
feet downward from the parent cloud, rotate or spin like a top,
and last a few minutes before dissipating.
These funnel clouds rarely touch the ground and typically do not
pose any sort of hazard. The atmospheric conditions that these
funnel clouds develop in do not support strong, damaging
tornadoes. However, on extremely rare occasions, these funnels can
briefly touch the ground and produce very minimal, if any, damage.
If threatening weather approaches, move indoors to a place of
safety. The National Weather Service will continue to closely
monitor the situation.