The past week was spent in Rogers Pass, working on a CAA Level 1 course.
Travel was limited due to the nature of the course, but we had groups in the
Loop,
Illecillewaet and Connaught drainages over a period of 3 days mid-week.
20-40 cm of snow fell over the week, with accompanying moderate winds from the
NW
and W. The storm snow fell on a variety of old surfaces but mostly on weak
decomposing crystals that showed signs of faceting on sheltered aspects and
thin
suncrusts on solar aspects.
The bond between the storm snow and old snow was not good and instabilities
were
observed there, with easy to moderate sudden planar shears. The good news is
that
below treeline the storm snow was generally too soft to act as a slab. The bad
news
is that in wind effected areas this interface was more reactive (even in large
open
features below treeline).
We had limited observations in the treeline and alpine but there seemed to be
wind
affected snow and suspected windslabs up there.
A moderate natural avalanche cycle was observed Wednesday, with several slabs
size
2-3 noted, at treeline and in the alpine. On Thursday avalanche control for the
hiway triggered more size 2 avalanches. Driving out of the Pass today I
couldn't see
anything fresh, but the alpine definitely looked wind affected.
No avalanches were observed on the Xmas/Nov facet layer, but our intructor team
and
local avalanche forecasters were still conscious of the potential there.
Hope that helps William.
Mark Klassen
Mountain Guide
Corax Alpine Guides
mark@xxxxxxxxxxxx
www.alpinism.com
403/760-3337
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