A major winter storm has hit our region this past week. Large avalanches have run in the Interior Ranges and new ones are being reported each day. The Trans-Canada Highway has been closed for numerous days and transportation in the west has been severely effected. Canadian Avalanche Association has just issued another warning indicating that a large avalanche unexpectedly ran near Rogers Pass and it cleaned out 10 acres of mature timber! This avalanche ran as temperatures began to cool down in the Selkirk Mountains. This slide took out the entire winter snowpack - over two meters!
It is very difficult to forecast avalanche activity for the future. I’m writing on Wednesday morning and you were probably anticipating heading out on this past weekend. One thing I can suggest is that you play it safe for a little while until the Avalanche Centre begins to relax its warnings of high avalanche danger.
What does it take to reduce the danger during a large avalanche cycle? We had very warm and inverted temperatures this past week (up to 1,600 meters elevation in the Cariboos). I observed wet snow slides in the North Blue drainage that ran to their full path limits.
The danger does not reduce until the snow freezes again. This occurred on the night of Jan. 17 in our region. At low elevation, conditions have already become more stable due to this freeze. At higher elevations, such as treeline and above, the snow did not thaw and the storm snow now represents additional load on the old surfaces. It is very difficult to predict danger or snow stability on a cold snowpack after a storm.
This morning in Clearwater it started snowing on the existing rain crust base. The bond of this kind of new snow onto crust is another area for concern to backcountry travelers. When the new snow is moist, the bond is often quite strong. If it is cold, the new layer may be prone to avalanches on the slippery surfaces.
If I were going skiing with my family or friends during this cycle of High Avalanche Danger, I would be wise to stay close to home and familiar terrain. An example of a place to go would be to enjoy the inbounds skiing at Sun Peaks with a short but non-commiting look at conditions in the backcountry. Transceiver, shovel, and probe are essentials. Again, check the Avalanche Centre Public Bulletin for the latest information on avalanche danger.
- Stephen Ludwig is a CAA Professional Member and an ACMG Certified Ski Guide. This column sponsored by Snowy Mountain Alpine Tours and Chalets. See SNOWYMOUNTAIN.CA