Avalanche Forecast
Issued: Jan 9th, 2013 9:41AM
The alpine rating is Storm Slabs and Wind Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Fair
Weather Forecast
Thursday: Expect mixed skies with some sunny breaks later in the day. Temperatures should reach -10 and winds turn to light northerlies.Friday & Saturday: A ridge dominates giving mixed skies, light northerly winds and cool alpine temperatures. Valley cloud is possible.
Avalanche Summary
Avalanches up to 2.5 have been reported, predominantly windslabs failing naturally and with explosives in lee locations. Isolated rider triggering has also been reported.
Snowpack Summary
The recent storm has brought up to 60cm of snow. Consistent southwest winds have redistributed the new snow (dramatically in some areas) to create widespread windslabbing on lee and open features in the alpine and exposed treeline. Where the wind has been strongest, windslabs are much lower on slopes than normal.There have been avalanches reported both within the storm layers as well as at the initial storm interface, the January 4th layer. This layer consists of small facets, surface hoar (up to 12mm) in sheltered treeline and below treeline areas and sun crust on steep south and west facing slopes. The bonds with the facetted snow are improving while the surface hoar &/or sun crust interface is weak. There are reports of Sudden Planar shears (fast & clean) in compression tests and âPropagation Likelyâ results in extended column tests on the preserved surface hoar.The midpack is well bonded and strong. The November 28 surface hoar is still being found in isolated, sheltered below treeline locations buried 120cm. The deep crust/facet combo from early November still exists and concern remains (although unlikely) for triggering this layer from a shallow spot or with a heavy load.
Problems
Storm Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 10th, 2013 2:00PM