Today I ski toured out to the Nose, which is a ridge that extends north
from the 'other' side of the Whale's Back on Evening Ridge near
Whitewater Ski Resort. I had a fun ski down, but had to ski cautiously
for two reasons. The first was low coverage. There are many small
trees that have yet to be covered and in many places I had to pick my
way down through them. The other reason was the surface hoar buried on
November 29. This was the main objective of my trip, to poke around in
the snow and get an idea of the extent of this layer.
I found it on southern (solar aspects) slopes and on an east facing
slope. I didn't bother looking on northern slopes because I knew it was
there based on the snow profile I did in the Whitewater snow study plot
on Monday. In all cases, it was 30-50cm down. It was not apparent on
some solar slopes that would have received direct sunlight, instead I
found a melt/freeze crust. On shaded solar slopes (in the forest) I did
find it. And, it was definitely there where I looked on the eastern
slope. The snow covering the layer has settled into a moderately
cohesive slab. The compression tests I performed were not conclusive,
including in the Whitewater study plot, except on the eastern facing
slope where the layer failed suddenly with moderate compressions. Hmm,
what to make of this?
The surface hoar layer appears to be widespread on all aspects except
sunny slopes where it may exist in isolated pockets. It doesn't appear
to be too reactive (easy to trigger) except in pockets on certain
slopes. While there hasn't been much, if any, natural avalanche
activity and little skier traffic to trigger this layer since the storm
that buried it, I have to wonder, do we have a sleeping dragon out there?
As the winter progresses and we start to venture out into the
backcountry, I feel a cautious approach would be prudent. I know I'll
be avoiding steep slopes, convex rolls and unsupported terrain and
generally treading lightly on my next few trips.
Craig Hollinger,
ACMG Assistant Ski Guide.
_______________________________________________
These observations and opinions are those of the person who submitted them. The
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nature of mountain weather and terrain. Application of this information
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