Avalanche Forecast

Issued: Dec 1st, 2011 9:22AM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is low. Known problems include Wind Slabs and Persistent Slabs.

Avalanche Canada jlammers, Avalanche Canada

Summary

Confidence

Fair - Due to limited field observations

Weather Forecast

Friday- Minimal snow expected. Winds moderate to strong from the north. Freezing level at about 550m.Saturday/Sunday- A ridge is expected to dominate the region bringing high cloud, very limited precipitation, moderate northerly winds and freezing levels at, or near surface.

Avalanche Summary

Widespread size 2 natural activity reported from the region on wednesday. 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 day will have created pockets of touchy windslab that will be lingering on lee and cross-loaded features at treeline and in the alpine; forecast strong N'ly winds may reverse & complicate the pattern with E through S facing slopes building new ones. I don't know much about the mid-pack but I suspect it's building strength. 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. It's still November (just barely), so we only have a teenage snowpack at best: variable, unpredicable, maybe moody. I suggest giving the snowpack a few days to reveal its secrets.

Problems

Wind Slabs

An icon showing Wind Slabs
Expect touchy windslabs in lee or cross-loaded terrain. The nature of this problem will become more complicated with forecast northerly winds.

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

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 4

Persistent Slabs

An icon showing Persistent Slabs
Where it exists, this layer may be capable of producing highly destructive, full depth avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

3 - 6

Valid until: Dec 2nd, 2011 8:00AM