Toolman, thank you.
As I watched alpine snow melt delay further and further and start at least one month later than normal in the Bow Watershed, I observed the Upper Bow was much lower and greener in colour than normal. Its colour reminded me of the Cowichan River of my youth. Curious about the temperature I measured it at a surprising 11C in late May when it is normally 4C during run-off. Outside air temperatures in the Upper Bow Valley were slightly below average all spring so the water was not being warmed by the air as much. I have a personal theory (don't shoot me, I have no scientific training), that since the water was more clear and much more shallow than normal, that the river bottom was absorbing higher than normal amounts of incoming solar radiation and thus the water is warmer. Thoughts fellow fisher folk?