Another Avy Death in ID

:'(

Saw this on TGR.
The thing that got me was the pictures of the terrain where it happened.
Looks fairly benign and not that big a slope and plently of trees above and below.

www.ktvb.com/news/localnews/stories/ktvb...alanche.cd416d6.html

A good reminder that trees aren't a safe bet.  I've heard the rule of thumb that trees are only adequate anchoring if they're too tight for you to ski through. 

We had a friend flushed through a grove of small pines (christmas trees) last year on a slope that the guides had "never seen slide".  She came out alive, but it was a sobering reminder, as is this.

Also, that's a big god damn slide.  Wind-loading from the ridge on the other side?  Remote trigger from a weak layer out in the open, near their entrance?  Scary.

Actually, looking at that first picture again, looks like the crown ran right in line along the divide between the trees and the open slopes.

Just in case you thought it was safe to go into the woods - scary!

The trees do look like a perforated line on the page - at least in that one zoom area of the picture.

Here is more detail from the IME:

www.mtexpress.com/index2.php?ID=2005125173

SS

Trees inhibit avalanche formation by a few key mechanisms:

- Intercept snowfall.
- Foliage alters radiation exchange. ( Inhibits some types of recrystallization and/or surface hoar formation. )
- Anchoring snowpack.
- Tree bombs disrupt cohesive slabs.
- Snowpack below thick trees isn't subject to the same harsh environmental conditions as snowpack the faces the open sky.

The area in which this avalanche occured has large areas of open slope. In terms of the elements listed above, the trees might as well have been non-existent. The slope is also small and decidedly non-threatening - especially in the context of the surrounding terrain. Middle ground terrain fosters perception problems because such terrain is neither clearly dangerous nor clearly safe. Evaluation is difficult. The amount of snow required to carry a skier downslope is amazing small; the amount of snow required for a complete burial is amazingly small. Or stated simply, the slope shown above contains enough snow to injure or kill a single skier many times over.

Imagine that slope without the trees.

The slope is also small and decidedly non-threatening - especially in the context of the surrounding terrain. Middle ground terrain fosters perception problems because such terrain is neither clearly dangerous nor clearly safe.

Good observation. What got me about the picture was that it is very similar to terrain that Snow Bell and I recently traversed through on a trip to Lane and Eagle Peak from Narada Falls. It involved a lot of traversing through terrain very similar to this in terms of non-threatening, kinda middle treed ground with clearings. I remember while on the traverse ( and it was long) that a part of me felt safe because of the trees and smallness of the slopes and I had to constantly remind myself that I was in serious avalanche terrain and keep good protocol and awareness. It's easy to get complacent in terrain like this.