USGS question

I'm still a newbie to erie steelheading. My question is what do you guys look for on the usgs gauge at walnut to indicate good conditions for fish to enter? I saw a few weeks back it jumped up over 100cfs and assume that's good for them to enter the tribs. But today I saw it only jumped up to about 20cfs.

You'd be surprised at how little water they need to get up Walnut. I've fished there on days with a flow of 20-30 CFS and watched several jump the small jack dams there and head on south.

One thing I've become convinced of on the bigger tribs - water temp is more important than water level to get fish in to stay. Those fish can swim through inches of water to get to where they want to go although higher flows are important to get em upstream.

As for what it will be like to actually fish, 60 CFS will get you a decent drift on Walnut. 100 will usually mean there's some color and just about prime. Over 150, I'm usually looking for smaller water though not always.