Doctor, you did it, we have a pulse!
It has been a little frustrating watching conditions: Lots of fits and starts due to the crazy weather patterns, snow, ice dams and the like; but we're starting to see definite signs that things are moving.
It's likely going to be a long road yet, so we'll just have to keep an eye on things, but at least the first signs are there. What it's going to take now is a good week to ten days of stable weather with lots of sun to get things really moving.
And you don't necessarily need all of that time to be above freezing (although that certainly helps). What really helps during the early stages is something we have a lot of: Pine and fir trees. Yes, you read that right... I know, there are a lot of you out there that think we're nuts already with all the seemingly oddball stuff we post, but it's true. Well, not that we're nuts - mostly... but we do post some seemingly strange stuff that doesn't seem to connect to steelheading at all.
The reason we mention the pine and fir tree connection is that where you have heavy concentrations of this type of ground cover along the streams, they help absorb and re-radiate lots of solar horsepower simply because they are much darker than the snow-covered ground. This actually promotes melting, even when air temps are still below freezing. Melt water getting into the streams on a daily basis is what causes that heartbeat-like signature you are seeing in the graphic, and lots of melt water is what helps open up streams with heavy ice-cover through the simple process of erosion.
As more snow melts around the dark tree cover, it also exposes the darker underlying ground which absorbs sunlight instead of reflecting it like snow. This accelerates warming which accelerates melting which accelerates the process that opens up the streams. Get enough open water and the stream beds absorb solar radiation which causes stream temps to rise; ultimately triggering the steelhead to begin their upstream migration.
So yes, expressed as a simple mathematical equation: (Solar Radiation + Pine Tree) x Time = Steelhead.