Avalanche Forecast
Issued: Dec 4th, 2011 8:39AM
The alpine rating is Wind Slabs and Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Poor - Due to limited field observations
Weather Forecast
The ridge of high pressure is forecast to continue to bring clear skies to the region on Sunday night and Monday. There is a temperature inversion forecast to move into the area from the Northwest. This means that it may be warmer in the Alpine than it is in the valley. This condition should be fairly short lived on Monday, and then replaced with below freezing temperatures down to the valleys by Tuesday morning. Strong South-westerly winds are forecast for Tuesday morning as a fast moving cold front move through the region. The ridge of high pressure should re-build on Wednesday, and there may be another period of above freezing temperatures in the alpine.
Avalanche Summary
No new observations have been reported. Any observations from the field are welcome. Please send to forecaster@avalanche.ca
Snowpack Summary
Expect to find around 200cm of snow near treeline. In the alpine there's either more or less depending on local wind patterns. I suspect last weekend's storm snow is settling into place and gaining strength. The snow and wind that occurred over the last few days will have created pockets of touchy windslab that will be lingering on lee and cross-loaded features at treeline and in the alpine. Forecast northerly winds may stiffen the current wind slab and/or redistribute surface snow creating new ones. A rain crust that developed on November 27th is about 20-35 cms below the surface (elevation dependant). It's about 2 cms thick at 1700m and is reportedly 'bullet-proof' closer to valley bottom. Some reactivity has been observed on this layer below treeline.Closer to the ground is the early November surface hoar; somewhere around 50 cm above ground or 150 cm below the surface. It may be difficult to trigger this layer but has a sudden planar characteristic. I also suspect a lingering rain crust down there.Finally, 2 cms of light snow fell on November 2nd burying a layer of surface hoar. It's not an issue at this point, but it's something to keep on your radarIt's still November (just barely), so we only have a teenage snowpack at best: variable, unpredictable, maybe moody. I suggest giving the snowpack a few days to reveal its secrets.
Problems
Wind Slabs
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 5th, 2011 8:00AM