Avalanche Forecast
Issued: Dec 9th, 2011 9:30AM
The alpine rating is Wind Slabs and Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Fair - Due to variable snopack conditions
Weather Forecast
The ridge that has dominated the regions weather for the last week begins to break down on Saturday allowing a pacific front into the forecast area. The result will be high clouds and increased winds out of the W-SW clocking in between 65 and 80 km/h. Little or no precipitation is forecasted out of this system but the good news is that the door is once again open for storms to track across southern BC & AB. Temperatures on Saturday remain within seasonal norms: @ 1500m we can expect day time high's around -1 with overnight lows sinking to -13.
Avalanche Summary
There have been numerous avalanches both natural and human triggered from Size 2 - 3 in the adjacent forecast areas where avalanches have been failing near the ground on the crust/facet combo. If you have any observations from the field, please drop us an email: forecaster@avalanche.ca.
Snowpack Summary
We're off to a good start for early December with upper elevation snow depths that average a meter. It's been almost two weeks since our last significant storm and since that time the snowpack has suffered an unrelenting barrage of wind from around the compass rose. Wind exposed terrain is now a mixed bag of wind effected snow that varies from old hard windslabs to fresh small windslabs and everything in between. To travel safely at & above treeline you need to be able to recognize and avoid these potentially dangerous windslabs. This is the first part of the avalanche problem. Getting a little lower in the snowpack reveals some ugliness. A raincrust sits above large striated facets (sugar snow) on the ground. This is the classic Rockies house of cards setup that professionals throughout the region are concerned about. With numerous recent avalanches failing in this layer in the Rockies recently the chance of a large full depth avalanche remains a concern for backcountry travelers this weekend. Triggering an avalanche in this weak layer will result in a large & destructive avalanche that will likely be unsurvivable.This problem will not go away anytime soon. If I was putting together plans for the weekend I'd be combing through my terrain atlas (google earth) looking for slopes around treeline that are protected from wind. Once you're out in the field stay off of terrain features that are thin and weak. Rock's and/or tree's poking out of the snow are a good indication of thin weak snow. It's good practice to avoid terrain that is steep and rocky in general right now. Remember, it's only December and our snowpack needs some time to mature before we even start thinking about the bigger more committing terrain.
Problems
Wind Slabs
Aspects: North, North East, East, South East, South, South West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 10th, 2011 8:00AM