* WHAT...Flash flooding caused by excessive rainfall continues to be possible. * WHERE...Portions of Illinois, including the following areas, Boone, Central Cook, De Kalb, DuPage, Kane, Kendall, Lake IL, Lee, McHenry, Northern Cook, Northern Will, Ogle, Southern Cook and Winnebago and northwest Indiana, including the following areas, Lake IN and Porter. * WHEN...Until 7 AM CDT Sunday. * IMPACTS...Creeks and streams may rise out of their banks. Flooding may occur in poor drainage and urban areas. Underpasses may be flooded. Roads and streets may be flooded. * ADDITIONAL DETAILS... - Another round of showers and thunderstorms is expected late this evening and overnight. Swaths of heavy to very heavy rainfall with 2+ inch per hour rainfall rates are likely to occur within the watch area and may result in areas of flash flooding and cause rapid rises on area rivers, creeks, and streams. - http://www.weather.gov/safety/flood