Avalanche Forecast
Issued: Dec 18th, 2012 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Deep Persistent Slabs.
ian jackson,
Avalanche Canada
Good skiing can be found in sheltered locations. Remember, a stable snowpack in December is different than a stable snowpack in April. Many thin/ weak spots still exist in alpine features. Hopefully the forecast of 5-10 cms on Thurs comes true!
Summary
Weather Forecast
Wed: Alpine temps in the -10 / -15 range. 1-2 cms snow, up to 5 cm N of Lake Louise overnight. Winds moderate from the W.
Thurs: Alpine temps -10/-15. 5-10cms new snow with higher values N of Lake Louise. Winds light from S/ SW.
Fri: Arctic air moves in. Alpine temps -15/-20. Clearing skies. Winds light from SW.
Snowpack Summary
A few cm's of new snow overlies a slowly facetting snowpack. In the alpine, old windslabs exist and are visible as 'rippled' snow on the surface. These may be reactive to human triggering. The Nov. 6th crust is facetting out, and is now more of a facet layer than a crust in many places. This layer is giving hard to no results in compression tests.
Avalanche Summary
No new avalanches observed today by forecasters during a field trip in the Lake Louise ski hill backcountry.
Confidence
Problems
Wind Slabs
New snow is hiding old windslabs in lee terrain at and above treeline that may be sensitive to skier triggering. In the right terrain these could take the skier into a terrain trap.
- Be cautious as you transition into wind affected terrain.
- The recent snow may now be hiding windslabs that were easily visible before the snow fell.
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
We are seeing weakening of the Nov 6 crust in thinner areas due to facetting. Although we haven't seen activity on this layer recently, it is still the prominent feature in this years snow pack, and should be evaluated in bigger features.
- Carefully evaluate and use caution around thin snowpack areas.
- Be aware of thin areas that may propogate to deeper instabilites.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 19th, 2012 4:00PM
