I've always had better luck when the conditions are exactly as you described. If you haven't tried it, and like the topwater bite..I highly recommend the "ribbit frog" . you can get them at bass pro and other bait shops. They work similar to a buzz or chatter bait in open water, and like a frog on top of the duckweed and moss. The strikes are nothing less than ferocious, so be ready
I usually have better luck in the main creek, before the split, but I've caught several after the split as well. The quality fish have come from the main creek for the most part though.
Tight Lines !!