Avalanche Forecast

Issued: Dec 28th, 2013 8:29AM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs and Persistent Slabs.

ghelgeson, Avalanche Canada

South Coast.

Summary

Confidence

Fair - Due to the number of field observations

Weather Forecast

Synopsis: The current pattern seems to be stuck on repeat. NW flow dominates with very little action in store for the South Coast for the foreseeable future. Sunday: Freezing Level: 800m Precip: 1/2mm Wind: Light, NW.Monday: Freezing Level: 1200m Precip: 1/2mm Wind: Mod SW Tuesday: Freezing Level: 750m Precip: 2/4mm Wind: Mod NW

Avalanche Summary

A small loose avalanche on a south facing slope in the Duffey was reported on Friday. In the Sea-to-Sky region on Friday a few storm/wind slabs to size 1 were also reported.

Snowpack Summary

Snowpack depths vary greatly across the region with 130cm reported at treeline in the Northern Cascades but only about 60 cm along the Duffy. In general, the snowpack across the region is significantly thinner than average for this time of year. Terrain below treeline is still mostly below threshold for avalanche activity.At upper elevations previously steady southwest winds and modest accumulations formed wind slabs which may still be reactive on steeper, unsupported lee slopes. Below treeline rain has moistened what little snow there is. Previous weak interfaces within the snowpack appear generally well bonded and have been unreactive to recent snowpack tests. The exception to this seems to be in the north of the region where touchy surface hoar buried on December 12th sits about 30cm below the surface. This seems to be the interface to watch as the overlying slab develops. Early season riding hazards such as rocks, stumps and logs are lurking below the surface at treeline elevations and below.

Problems

Wind Slabs

Previously steady SW winds, modest snow accumulations and warm temperatures came together to create new wind slabs on Friday. These may still be sensitive to human triggering on steep, unsupported slopes in gullies and in the lee of ridge crests.

Be alert to conditions that change with elevation.>Be cautious as you transition into wind affected terrain.>

Aspects: North, North East, East, South East, South.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

Reports from the Duffey area indicate a touchy layer of buried surface hoar now sits under about 30cm of snow. This is likely the layer to watch as the overlying slab develops.

Avoid open slopes and convex rolls at treeline where buried surface hoar may be preserved.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 29th, 2013 2:00PM