Avalanche Forecast

Issued: Dec 13th, 2013 7:57AM

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

Avalanche Canada esharp, Avalanche Canada

Summary

Confidence

Good - Freezing levels are uncertain

Weather Forecast

A warm front will push across onto the south coast late Saturday. Freezing levels will rise before the the trailing cold front crosses the province on Sunday. Monday with be a pretty benign weather day ahead of the next low pressure system expected early in the week.Tonight and Saturday: Expect snow to start falling Saturday morning. This will turn to rain at lower elevations as the freezing level rises through the day from 600m to 1200m. Snow accumulations at higher elevations will range between 10 and 15cm. Southwesterly ridgetop winds will start as moderate but become strong later in the day.Sunday: Light precipitation will continue before tapering off overnight. Ridge top winds will slowly diminish and become more westerly. Freezing levels will drop slightly in the wake of the cold front.Monday: A brief break ahead of the next system is forecast with overcast skies, light southwest winds and freezing levels holding at 1000m.

Avalanche Summary

Small soft storm slab avalanche have been reported to be releasing on convex features.

Snowpack Summary

Snowpack depths vary greatly across the region with an average of 100cm at treeline. Terrain below treeline is still mostly below threshold for avalanche activity. Higher elevations received 5 to 10cm of new snow yesterday. Below 1400m much of this fell as rain. Moderate southerly winds formed thin windslabs in lee features in the alpine. These are are sitting on a variety of old surfaces: a crust exists wind scoured north and northeast slopes and surface hoar can be found in sheltered locations above 1900m. These layers could become reactive over the weekend as the overlying slab develops due to additional snow, wind loading and rising temperatures.At higher elevations a few crusts can be found near the ground, especially in thin and rocky areas such as glacial moraines .Overall the coastal snowpack is significantly thinner than the historical average for this time of year. Early season riding hazards such as rocks, stumps and logs are lurking below the surface at treeline elevations. In glaciated terrain the forecast snow might just be enough to hide open crevasses where supportive snow bridges have not yet developed.

Problems

Storm Slabs

An icon showing Storm Slabs
S-SW winds will continue to load lee features in the alpine and at treeline forming soft slabs. The chance of avalanches will increase throughout the day as the wind strengthens and the temperature rises.
Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>Avoid freshly wind loaded features.>The snowpack on glaciers is shallow be cautious of hidden crevasses and un-supportive snow bridges.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Dec 14th, 2013 2:00PM

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