Avalanche Forecast

Issued: Dec 29th, 2013 8:45AM

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 - Forecast snowfall amounts are uncertain on Monday

Weather Forecast

Synopsis: The current pattern seems to be stuck on repeat. NW flow directs the bulk of the moisture at the North Coast leaving the South Coast largely high and dry. Winds are the big story Monday and Tuesday. If you believe in Miracles, there's a suggestion of a storm that could reach the South Coast on Thursday night. Cross your fingers.Monday: Freezing Level: 750m Precip: 2/5mm 2/8cm Wind: Initially light & Variable building to Strong SW late in the afternoon.Tuesday: Freezing Level: 750m Precip: Trace Wind: Mod W switching NW in the afternoon.Wednesday: Freezing Level: 500m Precip: Trace Wind: Light, W.

Avalanche Summary

Observed avalanche activity was limited to one small soft slab release from steep rocky terrain was reported Saturday.

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

The region will likely receive a few cm of new snow accompanied by strong SW winds. Watch for wind slab formation immediately lee of both ridge crests and mid slope features. Stay vigilant for changing conditions as winds pickup after lunch.

Avoid freshly wind loaded features.>Use ridges or ribs to avoid pockets of wind loaded snow.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

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 30th, 2013 2:00PM