Rogers Pass was closed today for Avalanche Control, both in Glacier Park
and in the Province to the West. Most explosive controlled avalanches were
in the size 3-3.5 range, with one very notable size 4.
Skiers in the backcountry around Grizzly Shoulder reported that trail
breaking was up to 40 cm - and higher on the uphill side of the track.
They were able to trigger several size 1 soft slab avalanches in the trees,
which had surprisingly wide propagation. These slides were running very
fast, and gained lots of volume in a short space. The skiers opted to
retreat early in the afternoon, as the wind picked up, making skiing even
spookier. No one ventured any further up valley than Grizzly Shoulder
itself - a wise choice.
Like everywhere else, the Rogers Pass snowpack has a very weak facetted
base, and now has a very heavy layer of storm snow on top. Tomorrow, it is
expected to get warm, with freezing levels rising to 1500 meters. It is
important to remember that Rogers Pass rarely has such a weak, facetted
base - we even have some depth hoar in places! With the warm heavy slab
of storm snow resting on this, it is likely that backcountry users will be
able to trigger avalanches very easily.
With all the new snow, I expect the coming weekend to be quite busy.
Things may settle out a bit by then, but the instability in the snowpack is
here for a long time, and very careful terrain choice will be critical for
safe travel.
Sylvia Forest
Specialist, Mountain Safety Programs, MRG
Mountain Guide
_______________________________________________
These observations and opinions are those of the person who submitted them. The
ACMG and its members take no responsibility for errors, omissions, or lapses in
continuity. Conditions differ greatly over time and space due to the variable
nature of mountain weather and terrain. Application of this information
provides no guarantee of increased safety. Do not use the Mountain Conditions
Report as the sole factor in planning trips or making decisions in the field.
Please check out http://acmg.ca/mcr for more information.
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