Travelling light, I covered a few swims in 5 hours of fishing, but failed to connect with anything. The river was rising slowly, increase in temp from 42F to 43F. I wasn't the only one - others blanked as well (incidentally it sounds like I was a day early as people started catching on Monday....with temps at 45F).
It looks like more of the same in the coming days (although sudden drops in temps overnight won't help), so I may be out again in search for a barbel. Keep my options open though until I know for sure what the levels are like.