From the benchWith zero wind overnight and calm conditions through Sunday morning, the fog will keep light low and fish comfortable in the shallows — wade quietly and work the inside seams of every bend with your nymph rig before the rain arrives. Once the overcast locks in around midday, switch your attention to the flat, glassy water between riffles and watch for BWO rises; a size 22 Parachute BWO or Barr's Flashback Emerger presented on a long, fine tippet will fool fish that are actively sipping. Rain is coming by afternoon, so plan to be off the water or switch to streamers as flows begin to rise — big browns will turn aggressive in the first flush of dirty water. Get your best nymphing and dry fly hours in before noon.