National Weather Service Weather Forecast Office

Early morning on Tuesday August 14, WSR-88D radar from NWS Chicago/Romeoville detected birds as they left their morning roost locations. These signatures are known as "roost rings" and appear as circles radiating out from a roost location that increase in size as the birds disperse.

Roost Rings detected by KLOT Radar Aug 14, 2012

Roost rings detected around the Kankakee River in Indiana and near the Illinois/Wisconsin state line in northeast IL.	This radar image was captured about 40 minutes later. New roost rings are being detected along the Illinois River.