Avalanche Forecast
Issued: Dec 23rd, 2011 8:50AM
The alpine rating is Wind Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Fair - Intensity of incoming weather is uncertainfor the entire period
Weather Forecast
Saturday: 5cm of snow - strong southwest winds - freezing level at 1200mSunday: 20cm of snow - moderate southerly winds - freezinglevel at 800mMonday: 10-20cm of snow - moderate southwest winds - freezing level at surface
Avalanche Summary
Recent observations are limited to isolated human-triggered Size 1 fresh wind slabs. One was 20m wide by 20cm deep on a NE facing alpine slope.
Snowpack Summary
Alpine areas are wind-hammered with scoured and pressed surfaces, exposed crusts, and pockets of hard and soft wind slabs. Buried surface hoar and/or facets may persist 10-20cm below a weak rain crust on sheltered treeline slopes and below. Recent compression tests on a treeline slope produced easy to moderate sudden collapse results down 65cm on on this weakness where it was wind-loaded. Watch this layer as it gets more load and a thick cohesive slab develops, particularly below treeline where the buried surface hoar would be especially large. A strong mid pack overlies weak basal facets and depth hoar in shallow alpine areas. This deep persistent weakness may also deserve attention with more load.
Problems
Wind Slabs
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 24th, 2011 8:00AM