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The ACMG Apprentice Ski Guide Exam was operating in
the Frisby and Big Eddy Creek areas of the Monashee Mountains (just north of
Revelstoke) for the past week.
Weather was variable with regular light snowfalls,
mostly calm with light and variable winds associated with snowfall events,
generally cool temperatures, and a mixed bag of sun, cloud, and fog.
At treeline there's an average of 4 - 4.5 metres of
snow on the ground. At higher elevations and on the glaciers we couldn't reach
the ground/ice with 3.5 metre long probes, even from the bottom of 1.5 metre
deep snowpits--we estimated 5-6 metres of snow at these elevations. There is a
surface haor layer buried 25 - 50 cm down from the surface. Early in the
week, this layer was highly reactive above treeline with test results in
the easy-moderate range (fast clean shears for the pros), whumphing, cracking,
and a few small skier and skier remote (avalanches initiated by a skier's weight
from distances of 5 - 50 metres) triggered avalanches. Most of this activity was
limited to higher elevations, both on shaded, wind affected areas right at
ridgecrest and where there were buried sun and temperature crusts above the
surface hoar. At treeline and lower, the surface hoar was more variable in it's
reactivity and didn't produce the easy shears or whumphing/cracking observed at
higher elevations.
While indications were that the surface hoar
layer mentioned above was settling down a bit as the week went on, it's
certainly not gone. It's well preserved and large in some places and, while it's
not on every slope, it is widespread--we found it on the crests of the highest
ridges right down into the trees on all aspects. Just because you don't find it
where you are digging, it's safe to assume it's just around the next corner or
lurking on the next steep pitch.
Throughout the week, we observed a couple of large
natural avalanches (at least one was the right depth to be on surface hoar) and
isolated smaller naturals on the surface hoar on various aspects, mostly at
higher elevations. These slides were triggered by wind-loading and perhaps
cornice fall in some cases. Natural, loose, wet avalanches occurred regularly
when the sun came out--mostly at and below treeline. We also observed numerous
natural slab releases on sunny rock slabs where glide cracks were
showing.
Skiing was very good on high elevation, north and
north-east facing slopes all week. At and below treeline, there were breakable
sun and temperature crusts on all aspects with isolated bits of half-decent
skiing on steep, shaded pockets. Sunny alpine slopes were good early in the
week, got trashed by the sun mid-week, then froze up and were decent dust on
crust skiing again by Friday. Below treeline, on steep sunny aspects, there was
up to 50 cm of wet (near isothermal) snow by mid-week which then refroze as
temps dropped and cloud cover reduced solar radiation. It was sunny on Saturday
when we flew out, so steep south facing terrain was probably getting hammered
again.
We started skiing on smaller, steeper features late
in the week, but for the most part we stayed on moderate terrain all week,
avoiding large, steep slopes especailly those with unsupported, convex
rolls.
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