Avalanche Forecast

Issued: Dec 30th, 2013 9:12AM

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 - Timing, track, or intensity of incoming weather system is uncertain on Thursday

Weather Forecast

Synopsis: The South Coast remains largely high and dry Tuesday & Wednesday, but it looks like a change is in store for Thursday.Tuesday: Freezing Level: 800m Precip: Trace Wind: Lht, NWWednesday: Freezing Level: 800m rising to 1000m; Precip: Trace Wind: Light, NW.Wednesday Night: Precip: 2/8mm - 2/10cmThursday: Freezing Level: 1000m Precip: 10/25mm - 10/30cm Wind: Strong SW at 2000m, extreme at ridgetop.

Avalanche Summary

No avalanches were reported on Sunday.

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.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

Wind slabs may still be a problem on steep slopes immediately lee of ridge crests.

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

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

Elevations: Alpine.

Likelihood

Unlikely - 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.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 31st, 2013 2:00PM