The present invention is a method of operating a fuel cell stack and system that minimizes the potential for having a large pressure differential between the anode and cathode flow fields and a low relative humidity occurrence within the cathode flow fields. This is accomplished by tempering the downward transient in power demand seen by the fuel cell stack. The downward transient in power demand on the fuel cell stack is tempered by reducing the rate at which the power generated by the fuel cell stack is decreased and providing the excess power generated by the fuel cell stack to other parasitic components of the fuel cell system.