Thunderstorms capable of producing heavy rain are expected to develop this evening and become more widespread late tonight into the overnight hours across northern Iowa. The most intense rainfall rates of 1 to 3 inches per hour are likely and rainfall totals over 2 to 4 inches are expected by Wednesday afternoon, with some locally higher amounts over 4 inches possible.
A flash flood watch is in effect from 10pm CDT this evening through 7pm Wednesday evening. A flash flood watch means that conditions may develop that lead to flash flooding. Flash flooding is a very dangerous situation.