Hi All,
We just finished a fine ski touring week at the Valhalla Lodge in the
Southwestern Selkirk Mountains (Dec 26th-Jan 2nd). Below is a summary of our
observations.
Weather:
We enjoyed some clear weather early in the week, at times windy in the Alpine,
and some snowy/stormy conditions for the second half of the week. Daytime
temperatures at the Lodge (2100m/6900ft) were near zero early in the week and
oscillated around -9.0 for most of the week. As this last system moved through
the area, Moderated to Strong southerly winds near ridge tops picked up and
temperatures rose closer to zero again.
Snowpack:
Snowpack height at treeline in the area was 165cm, a pretty average value there.
During the storm that lasted from December 28th to January 2nd, we received 40
to 50 cm of new snow. This new snow was generally evenly distributed at
treeline and below. Some exposed treeline areas near ridge top and most alpine
areas saw lots of snow redistribution and slab build up from the Mod to Strong
southerly winds. This new snow is overlying a variety of suspect surfaces like;
variable wind slabs or wind affect above treeline, recent surface hoar to 20mm
and/or sun crust on steep solar aspects at treeline and below. This interface
is our next/current problem layer and should be carefully monitored in the near
future. The December 12th facet layer, now 10-15cm thick, was found 75cm down
from the surface. The mid and lower snowpack was generally stiff and well
settled.
Snowpack tests showed Easy (resistant planar) shears down 40cm on the December
28th surface hoar layer and Hard to Very hard (sudden planar) shears down 75cm
on the December 12th facet layer. Shears on the December 12th facets seems to
be gaining strength over the course of the week.
Avalanches:
Earlier in the week we saw evidence of the December 20th natural avalanche
cycle with several old size 2-3 slab avalanches both above and bellow treeline
on NE to SE aspects. December 28th was windy above treeline. Small but touchy
soft and hard slabs developed in steep lee slopes of southerly winds. We felt
several moderate size whumpfs at treeline throughout the week, less as the week went on (we suspect the December 12th facet
layer). As the storm progressed,
we saw some natural and skier triggered sloughs in steep terrain to size 1.5.
As it intensified and warmed up later in the week, we pulled back from
challenging to simple terrain. We observed some minor surface cracking with significant slab development in lee slopes from southerly winds near
ridge top.
By the time we left this morning, we hadn't seen any new slab avalanches.
This
will likely change/is changing in the near future as the December 28th surface hoar layer
gets buried deeper and the slab above it consolidate. As this occurs, the risk
for human triggered avalanches will increase.
In the meantime, keeping an eye on the weather trend is advised. There is plenty of great skiing to be add on simple terrain.
Happy new year!
David Lussier
Mountain Guide
Windows Live: Make it easier for your friends to see what you’re up to on Facebook.
|
_______________________________________________
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.
|