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The following was sent to me by Anna Brown at
Glacier National Park. She seems to be having trouble getting it into the MCR so
I am posting it for her. Apologies if you get this twice.
In the last 2 days there have been 3 near misses in
Glacier Park. Even though these have been reported in the industry exchange and
the bulletin I would like to highlight them as I think they are examples of the
complicated and difficult nature of forecasting the hazard and stability at
present.
Some details to start:
Feb.4 Surface Hoar is now
down 50cm to 115cm depending on elevation and location. The depth of the slab
can vary up to 20-30cm within 100m. Parties are still getting wumphing, remote
triggers, which given the depth of the surface hoar is impressive. The slab
above the surface hoar is now consolidated into a cohesive unit which breaks
into large blocks.
Let me start by saying parties have been able to go
into some steep terrain and ski obvious avalanche paths and without getting into
trouble; no avalanches triggered and there are not many natural avalanches being
observed. Example, both West aspect slide paths off McGill shoulder and skiers
left of Grizzly Shoulder from above the rock band (known locally as Puff Daddy)
have tracks across and down them. Unfortunately this can offer a sense of
confidence or "negative feedback". We skied it, nothing happened, so logical
reasoning would lead you to believe the slope next to it, similar terrain,
aspect elevation, angle etc. will be just as good.
I am pretty sure this is not the case.
Wednesday, February 21
The group involved skis
an average of 4 days per week, all winter, they were local to the area, at least
one of them has a CAA Level 1 training and all of them have recreational
avalanche training. They are fit, strong, experienced skiers.
1 p.m. Wed. Feb.21 in the area of Flat Creek on the
west side of the park across the Illecillewaet from Bostock/McGill parking lot,
a party of 6 were skiing the top of the NE facing slide path from 2100m off the
shoulder of Fortitude Pk. They were on their 2nd lap, first skier down triggered
a slab which knocked him down, carried him for 20m, then he was able to push out
and ski off the edge of the slab. The avalanche ended running 400m onto a bench,
breaking small trees in the runout. Estimate size 2.5, possibly on Feb.4 Surface
Hoar with a 65cm deep fracture line on 25-30 degree slope.
Thursday, February 22
A group of 4 skied down to
Glacier Station (CPR railyard across from Asulkan parking lot) from Napoleon
Spur (ridge off Cheops across from NRC gully). Slope aspect South, angle 30 deg.
They negotiated steep upper section triggering only a very small slab on a steep
roll. In the lower angle section in the bottom half of the run the first skier
down triggered a 80m wide, 200m long, 80-100cm deep slab that took him for
a washing machine ride, spat him out on the surface but he lost his skis, a pole
and other clothing. Bed Surface was Surface Hoar on Crust. Again this
group has skied in Rogers Pass for over 10 years, local to the area, ski a lot
all season, all had avalanche courses.
Summary:
The snowpack right now is surprising
experienced people, guides, forecasters and recreational skiers alike. We know
the layer is there. We know you can trigger it with one person. We know the
consequences are increasing as the slab depth increases. I would liken the
situation a bit to a minefield, with sporadic feedback coming to the skier from
the snow.
Please check in to the Rogers Pass Center, read the
bulletin and other forecasts, ask lots of questions and report any involvements
or observations from your days out there.
Anna Brown
ACMG Ski Guide
Mount Revelstoke
Glacier National Park
Box 350 Revelstoke, B.C. V0E 2S
250 814-5218
(office)
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