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Avalanche Forecast

Dec 18th, 2011–Dec 19th, 2011
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
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: Sea To Sky.

Confidence

Fair - Intensity of incoming weather is uncertain on Tuesday

Weather Forecast

Expect mostly clear skies on monday with light southwesterly winds and freezing levels at surface.On tuesday light snowfall is forecast with moderate westerly winds and freezing levels remaining at surface.Clear skies should prevail again on wednesday as winds switch to light and northerly with alpine temperatures dipping to -12.0.

Avalanche Summary

Recent observations include several easily triggered size 1 windslabs on lee terrain in the alpine near ridge crests.

Snowpack Summary

The early December dry spell left us with weak, large surface hoar and faceted powder on sheltered shady slopes, and a surface crust on sun-exposed slopes. They are now buried about 30cm down by soft slabs from last week and more recent (friday to saturday night) wind-transported moist snow. With rain occurring up to 1800m over the last few days, some of these weak layers may have dissolved below treeline where a rain crust has now formed creating a potential weak layer for the future. At higher elevations, a cohesive and touchy windslab now exists and still over-rides these weaknesses. The mid and lower snowpack are generally well settled and strong, but faceted at base of the snowpack. Avalanche activity on any basal layers is highly unlikely at this time.Check out the Forecaster's Blog link below for more general snowpack discussion and good advice.

Avalanche Problems

Wind Slabs

Fresh wind slabs will exist on lee and cross-loaded features at treeline and in the alpine.

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

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 2

Storm Slabs

New snow has created a consistent vail over the old surface from the December dry spell. Expect storm slab development at treeline and above.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2