I was up there today (from 3:00 p.m. til 6:45 p.m.) and the flows were in the 3750 range which is wadeable (it would be better at around 3200). I've waded when the flows were at 4000 but there are fewer spots and you need to be real careful where you step.
***** Just checked the flows and they've dropped down to about 3200.
The visibility was about 3-4 feet. Not too hot (low 80's) but later in the evening, around 8:00 p.m. will be the best time to be on the river. The forecast calls for wind tomorrow. Call Steve at Red's Fly Shop (509-929-1802) before heading out to the canyon and they will give the weather and river conditions.