Avalanche Forecast

Issued: Jan 26th, 2012 9:39AM

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

jlammers, Avalanche Canada

South Coast.

Summary

Confidence

Fair - Due to variable weather conditions

Weather Forecast

Friday: mix of sun and cloud and very light flurries / moderate northwest winds / freezing level at 600m Saturday: increasing cloud in the afternoon with snowfall developing later in the day / winds increasing to strong and southwest by the end of the day / freezing level at 700m Sunday: moderate snowfall / moderate southwest winds / freezing level climbing to 1100m

Avalanche Summary

A size 2.5 natural was observed on an alpine feature in the Duffey Lake area on Wednesday. In the Coquihalla area, widespread windslab avalanches to size 3 were reported on Thursday

Snowpack Summary

On wednesday night another 25-30cm of snow fell with moderate southwest winds adding to the 50cm of snow that fell with strong southwest winds earlier in the week. Add all of this to the 25-40cms that fell over last weekend that now sits on top of the previous cold, low density snow from the last week and you've got a great recipe for deep storm and wind slab development. In general, snowfall amounts have been greatest in the Coquihalla area over the past week with total snowpack depths at treeline amounting to 390cm. In the Duffey Lake area, treeline depths are closer to 220cm.Persistent weak layers lower down in the snowpack have generally ceased to be of concern, except perhaps in very isolated, thin rocky areas.

Problems

Wind Slabs

Continued snowfall and strong SW winds have set up deep new wind slabs on opposite slopes and terrain features.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 6

Storm Slabs

Numerous deep storm interfaces exist in the upper snowpack. Watch for triggering on steep or unsupported terrain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 6

Cornices

High winds, moderate temperatures and recent snow will have added to a cornice problem. Cornice fall will be easy to initiate and can become a trigger for the slope below.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 6

Valid until: Jan 27th, 2012 8:00AM