Areal Flood Advisory until 7:30PM for a good portion of the Chicago area generally north of Interstate-88

Areal Flood Advisory (light-green-shaded area on the highlighted map) for the following northern Illinois counties until 7:30PM CDT…

Lake, Ogle, Winnebago, Kane, McHenry, Boone, northwestern Cook and northern DeKalb Counties…

At 427 PM CDT, Doppler radar indicated numerous thunderstorms with
  brief heavy rain. These are moving to the northeast over the same
  areas of far northern Illinois. Up to one to two inches of rain
  has already fallen on already wet ground in some isolated
  locations today. This additional rainfall will cause minor
  flooding in the advisory area, generally north of I-88.

* Some locations that will experience flooding include...
  Rockford, Elgin, Waukegan, Arlington Heights, Palatine, Hoffman
  Estates, Buffalo Grove, Carpentersville, Wheeling, St. Charles,
  Gurnee, Mundelein, Algonquin, McHenry, Belvidere, Vernon Hills,
  Woodstock, Zion, Rolling Meadows and Loves Park.