My experience is after a cold front, the fishing is slim and none, and slim just left town. I have read it is because the high skies keep the fish deeper due to brightness, therefore harder to catch. There still somewhat active, just harder to locate and fish effectively. Don't know if that is the reason, but I pretty much stay home after a cold front moves through. I don't know the reason, but it sure slows down for me, fresh or salt, lake or stream. Maybe it is just confidence, but just can't get much to move on a rising barometer after a front.