Avalanche Forecast
Issued: Jan 9th, 2015 7:34AM
The alpine rating is Wind Slabs and Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Fair - Due to the number of field observations
Weather Forecast
Synopsis: The ridge of high pressure gives way to weak upper trough on Saturday bringing more cloud and unsettled conditions through Sunday. We could see flurries on the weekend but no significant accumulation. Ridge winds are generally light or moderate from the W-NW. The ridge should rebuild on Monday bringing drier conditions and more sunshine. The freezing level remains at valley bottom throughout the period.
Avalanche Summary
One observer north of Sparwood reported one natural size 1.5 slab avalanche and one remotely triggered size 2 avalanche on Wednesday, both sliding on the buried crust layer down 30-50 cm. On Tuesday, there was one report of a size 2.5 natural slab avalanche from Allison Peak in the Crowsnest Pass.
Snowpack Summary
Below treeline and on south-facing slopes there may be a melt-freeze crust overlying up to 20 cm of recent snow. At higher elevations the new snow has been blown into wind slabs in exposed lee terrain. The recent snow sits on hard wind slabs in exposed terrain, and low density faceted snow in sheltered areas. Up to 75 cm below the surface you will likely find a hard, thick crust which formed mid-December. This crust has overlying facets and surface hoar (up to 10 mm in sheltered locations at treeline and below). This layer seems variably reactive throughout the region. In areas where the overlying slab is thick and cohesive, large avalanches are possible at this interface. A crust/facet combo which formed in November seems to have gone dormant for the time being.
Problems
Wind Slabs
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 10th, 2015 2:00PM