UPDATE: Small cells are developing over Dupage County, but the main storm cells heading toward the northwest suburbs are just passing I-80 and entering southwest Kane County at 8:00 p.m.
A Severe Thunderstorm Watch was issued at 5:45 p.m. At 7:00 p.m. radar indicates storms just to the west of northwest Cook County traveling north-northwest. A cell is developing in DuPage County, but the majority of thunderstorms are south of I-80.
SEVERE THUNDERSTORM WATCH OUTLINE UPDATE FOR WS 535 NWS STORM PREDICTION CENTER NORMAN OK 545 PM CDT TUE JUN 21 2011 SEVERE THUNDERSTORM WATCH 535 IS IN EFFECT UNTIL 100 AM CDT FOR THE FOLLOWING LOCATIONS IN ILLINOIS
ILLINOIS COUNTIES INCLUDED ARE BOONE BUREAU COOK DE KALB DUPAGE FORD FULTON GRUNDY HENRY IROQUOIS KANE KANKAKEE KENDALL KNOX LAKE LA SALLE LEE LIVINGSTON MARSHALL MCHENRY MCLEAN OGLE PEORIA PUTNAM STARK STEPHENSON TAZEWELL WILL WINNEBAGO WOODFORD