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Avalanche Forecast

Dec 12th, 2012–Dec 13th, 2012
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low

Regions: Jasper.

Conditions are stabilizing but patience is advised before venturing into wind loaded alpine slopes.  Stick to sheltered tree line slopes. 

Weather Forecast

Temperatures will remain seasonal (Max -7 Min -15) with no snow in the forecast.  Light Westerly winds can be expected at tree line with moderate to strong winds in the alpine.

Snowpack Summary

Wind slab can be found on most lee slopes extending from the Alpine well into tree line elevations.  Expect variable wind loading patterns as directions vary with local terrain influences.  Cornices are well developed.

Avalanche Summary

An avalanche cycle occurred Sunday into Monday.  Slab avalanches to size 3 were observed on NE aspects at alpine and tree line elevations and in some locations, have stepped down to the basal facet layer.  Large cornice failure has triggered large avalanches on the basal facet layer as well. 

Confidence

Due to the number and quality of field observations on Thursday

Avalanche Problems

Wind Slabs

Wind slab is present on all open lee slopes from the alpine into tree line elevations. Several natural slab avalanches have been observed on this layer.
Avoid freshly wind loaded features.Be careful with wind loaded pockets while approaching and climbing ice routes.

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 2 - 3

Deep Persistent Slabs

Slab avalanches and large cornice failures have triggered this weakness on SE to NE aspects in the alpine.� Shallow snowpack areas� and along the edges of snow pockets will be likely trigger spots.
Avoid steep slopes below cornices.Be aware of thin areas that may propogate to deeper instabilites.

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 2 - 3