As of Wednesday, Dec. 13
Our mountain snowpack continues to be full of potential weaknesses that will eventually materialize when we finally get a significant amount of new snow. The big change is forecast to arrive on late Thursday and Friday – let’s hope it arrives with a vengeance!
The layer of facetted crystals that is overlain in some areas by surface hoar is still very much in evidence anywhere from 50 to 100 cm below the surface. The shears on this layer have however been tightening during the past week. Recent facetting has been taking place in the upper snowpack during the spell of cold temperatures, and in protected terrain surface hoar has developed.
Another variable to throw into the mix is the strong NE winds that blasted the mountains on Dec. 10. One look at the peaks that day gave a very visual picture of the snow that was being transported onto the lee slopes. The resulting stiff windslab can be found in some pockets of terrain.
What’s going to happen when it snows? Familiarity with the terrain could be a big factor when one tries to figure out what slopes to jump into and what slopes to avoid. Many slopes have run once and maybe twice already on the layer of facets. On others, the weak layers may begin to get bridged over. Rocky terrain that still has little snow cover will probably be suspect for a long while yet, as the recent cold weather has only continued to weaken an already "rotted" snowpack. As many have already speculated, perhaps the best solution would be a torrential downpour to the 3,000 metre elevation over the province of B.C.!
The forecast is calling for snow to begin falling late on Thursday. Temperatures should remain cool enough to produce snow in the valley for this first wave. We can expect heavier snowfall and warming temperatures for the next wave late on Friday, but cooling again by Sunday. By early next week, we should see a weak ridge begin to build.
The backcountry avalanche danger is rated MODERATE as of Dec. 13
. This will likely deteriorate with the forecast snow for the end of the week. Remember that conditions may change rapidly. For current conditions call the Whistler/Blackcomb Snow and Avalanche Info Line at 938-7676 or the CAA info line @1-800-667-1105. Or contact your local ski patrol.
