With heavy rains possible through Saturday, the National Weather Service says "another very dangerous flooding situation may be developing for southern Wisconsin."
The weather service issued a flash flood watch for an area from the southwest to south central, east central and southeastern Wisconsin.
Forecasters say the situation has many similarities to early June, when a series of storms produced massive downpours over several days and led to extensive flooding.
Thirty of the state's 72 counties have been declared federal disaster areas since then.