Avalanche Forecast
Issued: Dec 17th, 2012 9:30AM
The alpine rating is Storm Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeConditions vary greatly due to the track of the recent storm. Expect elevated danger in the south and west of the region.
Summary
Confidence
Fair - Timing, track, or intensity of incoming weather is uncertain
Weather Forecast
Tuesday: Light to moderate W winds. Alpine temp -15. Very light snow.Wednesday: Moderate SW winds. Alpine temp -12. Moderate snow (~15 cm).Thursday: Light SE winds. Alpine temp -10. Moderate snow (~15 cm).
Avalanche Summary
Several size 1-1.5 loose snow and soft slab avalanches have been observed in response to new snow and wind loading. A size 2 slab failed naturally on a cross loaded SE facing alpine slope. Explosives triggered a size 2 soft slab which stepped down to the late November surface hoar layer in a steep rocky area in the Selkirks on Sunday.
Snowpack Summary
Up to 60 cm of low density new snow has formed wind slabs in exposed lee and cross-loaded terrain in the alpine and at treeline. In areas sheltered from the wind, the new snow is sluffing fast and far. Older wind slabs are also buried on northerly aspects in the alpine. Overall, the upper snowpack is reported to be settling well. The late November surface hoar, down 100-140 cm (between 1500 and 2000 m), is producing moderate to no results in snowpack tests, with isolated sudden results. The early November crust, down 150-230 cm, has produced occasional sudden results in snowpack tests. Professionals are still cautious about these lingering persistent slab problems, but the likelihood of triggering continues to decrease as the overlying snowpack builds and continues to gain strength. Be wary of steep complex terrain with a shallow snowpack, where triggering a persistent weakness is more likely.
Problems
Storm Slabs
Weaknesses within and below the storm snow will need some time to settle and bond. Be alert for wind slabs behind ridges and terrain breaks.
Stay off recent wind loaded areas until the slope has had a chance to stabilize.>Be cautious of sluffing in steep terrain.>
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 18th, 2012 2:00PM