2012 02 27 Improving Conditions?
I used to think that managing avalanche risk simply required one to forecast avalanches, and everything else then just fell into place. Boy was I naïve! First, it’s impossible to predict when & where (and for what reason) specific avalanches occur on specific slopes with certainty; that’s the bad news. The good news is that we do a pretty good job at predicting general avalanche trends. Over the past weekend in many of our regions there was abundant new snow, many obvious clues including natural avalanches, and High avalanche danger. Danger Ratings are now lower at Considerable where I suspect they’ll remain for the next few days. We’re pretty confident that the likelihood of natural avalanches is declining but that triggering one yourself remains likely. I just can’t tell you exactly where or when, or how large it will be.
That brings me to my second point. Where we go, and what we do while playing in the mountains has a huge effect on where and when avalanches release. We trigger them ourselves! Managing avalanche risk requires managing ourselves. That’s especially true these days!
I think it’s actually going to be trickier to select terrain and how you travel in it this week (Feb 27 to March 02) with Considerable Danger Ratings (Orange, Level 3) than it was this past weekend. The reason is that decision-making Confidence will be low. Conservative decision-making is easy during a storm or when the mountains are rumbling with large avalanches. It’s after the storm, when the snow remains structurally weak that decision-making is most difficult. The graph below shows the relationship between accidents and decision confidence. In other words, I’m worried!
On the one hand conditions are improving and danger ratings have come down one step. On the other hand obvious clues aren’t that obvious right now. They’re there, but I expect them to be more subtle: fewer natural avalanches mean the snow is stronger, but is it strong enough to ride or primed for triggering? You ride one slope and it was lots of fun, but consider this: Was it safe, or were you simply lucky to have missed the trigger points? What about that slope over there, how do you assess that one? What about tracks? Do they show stable conditions?
The way we see it at the CAC forecasting office is that conditions are actually more difficult today than they were a few days ago. There are lots of reports of remotely triggered avalanches where a person starts a chain reaction under their feet and releases slopes at a distance, maybe that one above you. With fewer natural avalanches people are going to start leaving the trees, sticking their noses out into more terrain, and testing more slopes. Slopes with tracks are going to tempt you and you’re going to have to assess whether they really are a sign of intelligent life, or people under the spell of the sirens’ song (powder & blue sky beckons…).
This week there will be clues to help you evaluate conditions, but they could be subtle and need a bit of detective work to notice. An open-eyed, curious but cautious approach should serve you well. Right now I don’t think it’s about the snow (we know it’s complex and structurally unsound), it’s about us. We have to balance desire and discipline “as conditions improve”.
ilya storm
