South Rockies

Fair - Due to variable snopack conditions

A strong ridge of high pressure remains anchored off the BC coast & will continue to influence the region through the weekend. The good news is that the ridge begins to break down early next week which means that conditions will be more favorable for snow in the interior ranges. For Friday, winds will continue to be out of the W-SW at light to moderate values. We'll see a slight temperature inversion in the Alpine Friday, but I'm not expecting anything too dramatic. Freezing levels should creep down to at least 800m, likely a bit lower on Friday night. Mostly sunny skies are forecasted for Friday with a daytime high of -4 @ 1500 m & an overnight low of -15. Saturday looks very similar with a smidge more cloud building into the region.

We have a report of a large avalanche (size 3.0) triggered by a snowmobiler in the Mt. Corbin area last weekend. In short, it sounds like like some snow stiffened by the wind released down deep on the weak facets. 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: [email protected].

We're off to a good start for early December with upper elevation snow depths that average a meter. It's been about 10 days 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. Folks with extensive experience and education should be able to manage this hazard.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. While there hasn't been any activity reported on this layer for the last few days, the potential for large full depth avalanches remains a concern for backcountry travelers. 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.