Avalanche Forecast

Issued: Dec 10th, 2014 8:04AM

The alpine rating is high, the treeline rating is high, and the below treeline rating is high. Known problems include Storm Slabs, Persistent Slabs and Loose Wet.

Parks Canada danyelle magnan, Parks Canada

An intense storm is causing dangerous backcountry conditions (and terrible ski quality). Avoid all avalanche terrain and give the snowpack some time to adjust to the new load in the wake of the storm.

Summary

Weather Forecast

The forecast is warm, wet and windy; avalanche hazard will increase. Freezing levels today are around 2300m, with up to 15mm of rain, alpine temps of +3'C and S winds gusting to 85km/hr. Overnight, freezing levels should lower to 1300m and up to 10cm of snow are expected. Thurs and Fri will be cloudy with flurries, moderate SW winds, highs of +1.

Snowpack Summary

A ~25cm storm slab, which will be thicker in windloaded areas, will bond poorly where it overlies surface hoar or sun crust. Below 1600m it will bond poorly to a rain crust. Rain, occurring to at least 1900m is adding more load. The Nov persistent weak layers, down ~105 and ~140cm, still have the potential to create large avalanches.

Avalanche Summary

Natural avalanche activity started yesterday, with numerous size 2-2.5 avalanches occurring from all aspects and running onto avalanche fans. By the end of the day avalanche debris was becoming wet in character. Widespread avalanche activity is expected today due to rapid loading by rain and wind.

Confidence

Problems

Storm Slabs

An icon showing Storm Slabs
A heavy storm slab is building rapidly with moderate precipitation, warm temps and strong winds. It will bond poorly to the snow below and natural avalanches are occurring. Storm slabs may step down deeper resulting in very large avalanches.
Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

2 - 3

Persistent Slabs

An icon showing Persistent Slabs
Persistent weak layers that were very reactive earlier this season are expected to wake up again with the rapid loading that is occurring. These layers are capable of wide propagations and producing very large and destructive avalanches.
Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 3

Loose Wet

An icon showing Loose Wet
Rain to at least 1900m is saturating and weakening the snow. Below 1600m the wet surface snow will slide easily on buried crusts.
Be cautious of sluffing in steep terrain.Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Dec 11th, 2014 8:00AM