You should be hoping for clouds, but not rain. You should also be hoping for cool weather so they might generate a little bit. If you really want to HOPE for something. Hope they run 1500 CFS all day.
The river only runs about 4 miles before it hits the White and the last mile or so IS NOT great water. You might end up floating it twice in one day. When water comes up, you'll quickly know it. Small river. Generation quickly increases depth and flow rate. The river sounds louder and the water line along the river is quite evident.
You might also end up spending significant time on sections of the White as well.
Twin River Fly Shop in Norfork and Steve Daly's fly shop in Cotter are two good sources of information with lots of streamer fanatics involved.