Sounds like your weather and water temp is about the same as here in Central IL. I think you are fishing to deep at 12 -16 ft. I caught a lot of fish from the bank down to 7 feet this weekend. Most I caught were aroude 6 - 7 ft deep. Id concentrate a little shallower. I was using 3/8 oz weights slow trolling. The females I caught still had eggs in them so I wouldnt go full bore post spawn just yet.