* WHAT...Flash flooding caused by excessive rainfall continues to be possible. * WHERE...Portions of Illinois, including the following counties, Central Cook, DuPage, Eastern Will, Grundy, Kane, Kankakee, Kendall, La Salle, Northern Cook, Northern Will, Southern Cook and Southern Will and northwest Indiana, including the following counties, Lake IN and Porter. * WHEN...Until 3 AM CDT Wednesday. * 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... - Multiple rounds of showers and thunderstorms with rainfall rates up to 1 to 2 inches per hour will be possible this evening until later tonight. The highest chance for flooding will be in urban areas and locations that received heavy rainfall over the last several days. - http://www.weather.gov/safety/flood