Portions of the area have recently received heavy rainfall and other areas can handle some rainfall. Widespread thunderstorms are expected late today into tonight which could produce widespread heavy rainfall. High rain rates, training of storms, and slow storm movement will create to the potential for flash flooding across much of the area. Some chances for heavy rainfall exist across northern Iowa today, however, the greater threat for heavy rainfall and flash flooding will come early this evening into the overnight hours as more widespread thunderstorm activity is anticipated.
Torrential rainfall is possible tonight. High rainfall rates of in excess of two inches per hour, combined with slow storm motions and possible training of storms will lead to the potential for flash flooding. Rainfall amounts of one to three inches may be common where storms persist, with localized amounts of 4 to 6 inches possible.
Water may cover roadways, and rapid rises on local streams and creeks will be possible. A flash flood watch means that conditions may develop that lead to flash flooding. Flash flooding is a very dangerous situation. You should monitor later forecasts and be prepared to take action should flash flood warnings be issued.