Avalanche Forecast
Issued: Dec 8th, 2011 9:02AM
The alpine rating is Wind Slabs and Deep Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Fair - Due to limited field observationsfor the entire period
Weather Forecast
Friday: Mostly sunny and dry with light winds. The strong temperature inversion continues with above freezing alpine temperatures and the possibility of valley cloud. Saturday: Increasing clouds and light southwest winds with light precipitation starting in the evening. The temperature inversion is expected to dissipate with freezing levels as high as 1400m. Sunday: Light snowfall, freezing levels lowering to 900m, and light to moderate southwest winds.
Avalanche Summary
There have been no recent avalanches reported. Although the likelihood of triggering deep persistent slab avalanches is low, the potential consequences are still very high.
Snowpack Summary
Basal depth hoar with an associated crust is prevalent in thin snowpack areas, and especially problematic where it is overlying summer firn. Above that, and down 1-2m, are two more crusts mixed with facets, depth hoar, and surface hoar. The overlying snow has recently settled and stiffened and the facets have started to round and strengthen, but recent compression tests in a shallow snowpack area produced moderate sudden collapse results on this deep persistent weakness. The snow surface is wind hammered in wind-exposed areas, crusty on sun-exposed slopes, and faceted powder with large surface hoar on shady sheltered slopes. A thick rain crust is down 20-40cm and extends up to treeline elevations.
Problems
Wind Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 9th, 2011 8:00AM