The forecast calls for more rainfall throughout Saturday, which is also the third day of Lollapalooza in Chicago’s Grant Park. Fox Chicago Meteorologist Mark Strehl has the forecast for Saturday. What to Expect:Heavy rains might be possible in some parts of the area with localized flooding. A Flood Watch is in effect for most of the Chicago area and Northwest Indiana through 7 p.m., according to the National Weather Service. Another Flash Flood Warning was issued for parts of DuPage County until 11:45 a.m.