Avalanche Forecast

Issued: Dec 1st, 2015 7:55AM

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

triley, Avalanche Canada

Sea To Sky.

Avalanche danger is increasing as a series of storms move in from the southwest. These danger ratings are based on 10-20 mm of precipitation by Wednesday morning, and should be considered on the low side if you receive more snow in your area.

Summary

Confidence

Poor - Due to the number and quality of field observations

Weather Forecast

A series of warm Pacific storms are forecast to move into the region over the next few days. Expect 10-20 mm of precipitation by Wednesday morning combined with strong southeast winds and rising freezing levels. The next storm should hit the coast on Wednesday evening and continue through most of Thursday. Friday should be another lull between storms.

Avalanche Summary

No recent avalanches have been reported. I suspect that new storm slabs are bonding poorly in some areas and may be easy to trigger with light additional loads.

Snowpack Summary

Below you can see a description of the "foundation" of the snowpack, everything is about to change with a series of snow and wind events forecast over the next few days. Forecast storm snow is likely to build slabs, which may bond poorly to the current cornucopia of surfaces including hard slabs, crusts, facets and surface hoar. The snowpack is highly variable across different aspects and elevations. There is anywhere from 30-150 cm on the ground. Previous northerly outflow winds scoured upwind slopes back to a firm crust, and created wind slabs on lee aspects, which are gradually gaining strength. Shallow snowpack areas are rotten (facetted).

Problems

Storm Slabs

New storm slabs are developing due to the on-going storm. These storm slabs may not bond well to the old surface of crusts, wind hardened snow, facets, or surface hoar.

Minimize exposure during periods of heavy loading from new snow, wind.>Avoid freshly wind loaded features.>Use ridges or ribs to avoid pockets of wind loaded snow.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 4

Valid until: Dec 2nd, 2015 2:00PM