If you want up to the minute, and accurate, information...you can call the BLM office up there @ 541-416-6718. They recommend no less that 800cfs for rafts. And the lower the water level, the better the fishing is for smallies. But the lower the water, the longer it takes to complete the 70 miles drift.
X 2 on Woolly Buggers, especially when dressed w/ a metal cone or metal eyes at the front...VERY deadly! Small jigs are good too. I wouldn't rule out surface popper plugs too, if you have 'em.
Good luck.