Thousands of people living, camping or recreating along rivers in northern Michigan face an urgent flash flood threat after dam operators opened floodgates on two major dams, triggering dangerous and fast-rising water downstream , according to the National Weather Service (NWS). Flash flood warnings remain in effect for parts of Manistee, Alcona and Oscoda counties following floodgate releases at the Tippy Dam on the Manistee River and the Mio Dam on the Au Sable River. The warnings were issued