They do indeed run to the flow from Truman. I can tell you from my experience there is no way to know when to be there. It's a hit and miss, if you hit it's great, if not there's still generally something biting. There are just to many variables, water temperature, flow, shad movement, and the list goes on.
Top water walk the dog lures, jigs with a plastic trailer and rods with a lot of reach will improve your chances.