As the CAA has stopped functioning for season and not many people seem to be
going out into the hills and reporting about it, this might help out;
On a ski mountaineering tour May 13-15th in the Mt. Columbia zone;
Valley bottoms melted out, hiking shoes a boon. Intense and severe
radiation. Clear skies, overnight lows of ?12, alpine highs of 12. Winds
L-Moderate from SW increasing with altitude. Some ridge top snow transport.
No new NATURAL avalanche activity observed. Soft Slabs triggered on Mt.
Columbia summit ridge (see ?Mt. Columbia/Catleguard? MCR report for details
and pics).
Snowpack Synopsis
GLACIER CONDITIONS:
Valley to 1900m: Innovative business man could set up a slurpy stand
anywhere in snow leading to glaciers.
1900m to 2200m; widespread melt-freeze crust supportive in early a.m.,
softening in p.m. creating either troublesome breakable double penetration
but mostly nice soft crust/corn depending on aspect/elevation. Snow on the
lower reaches of glaciers melting out super fast, bridges beginning to sag,
crevaces going bearback, snowplugs exposed and yellowing. What snow there
is, is isothermal. Here water has percolated deep into bridges weakening
them significantly. Roping up advised at the very least on lower reaches of
glaciers.
2200m-3200m; winter conditions beginning to change. Over 4 meters of snow
with strong bridges, no sags, only the big gapers visible. Above 2800
meters 5-10 cm of settled HST (recent storm snow) can be found.
SLOPE CONDTIONS:
Icefields snowpack very variable with isolated weakness? persisting in the
high alpine. First area of concern is the particular widespread weakness,
susceptible to human trigger, on high alpine- lee & cross loaded- SE and NE
aspects.
-2800-3700 m, 10-15 cm of settled storm snow over 20-35cm of denser snow
over a 3-4 cm windcrust/melt-freeze depending on aspect. On wind affected
slopes, especially SE, a soft slab has formed with a poor bond above the
crust. Seemed well settled below crust.. N and I suspect NW aspects, were
much better, well settled/bonded layers with preserved 5-15cm surface
powder. These slopes are susceptible to surface sloughing/loose snow
avalanches- with trigger.
-Below 2800 meters warmer temps have had an overall settling effect on the
snowpack. Isolated pillows are still visible, caution on convex features.
Next cycle of lower elevation solar aspect wet slides not running yet.
-Non glacier vicinity slopes are warmer and need careful evaluation as they
have had several melt-freeze cycles and are either bomber corn or ready for
wet slide initiation depending on time of day/aspect.
Outlook:
High Alpine:
Caution; SE-NE soft slab on wind affected slopes. Do not be deceived by good
overnight freezes. Daytime heating is just now beginning to affect alpine
slopes below the surface snow and into mid-pack. A resulting slide or
cornice failure could trigger a secondary early season weakness? avalanche
especially in the lower alpine zones where they are more prevalent. I
encountered cornices over 3600 meters that had a glazed top with moist snow
15 cm down. Below 3000 meters in the shade, moist snow down 30cm . Since the
alpine is currently in that temperature transition time and just beginning
to react to the day after day warm temps, all those nasties, such as cornice
fall, rockfall, snowballing, falling mushrooms, will in my opinion make even
North facing gullies not so user friendly. Increase caution with higher
night-time low temps. Widespread cornice failure has not yet begun, but?
Low Alpine:
A new cycle of wet slide avalanches will likely begin happening on steeper S
aspects very soon below 2800 meters or so. There are however many excellent
solar aspect corn snow slopes to be skied and soft North aspects too.
Maintain caution on windloaded and steep convex rolls here. Rockfall
potential will become prevalent in the next while.
Treeline and Below treeline; Wretched blood sucking parasitic pests still
abundant
Recommendations: These are tumultuous transitional times. In the mountains
conditions are very variable; stop, think, consider, be more conservative
until things even out and become more predictable.
Eric Dumerac
Rocky Mountain Vertical
ACMG Assistant Ski/Alpine Guide, CAA Level II, CSIA Level II Ski Instructor.
Long time ski tourer, pioneering alpinist, rock, ice, and mixed climber at
your service.
403-609-2965 Canmore AB.
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