The avalanche hazard will remain elevated as warming temperatures, strong to extreme winds, and more snow arrives on Sunday.
Mt. Simpson will be closed all day on Sunday, December 14, as avalanche control operations will be underway. Go to: https://www.pc.gc.ca for more details
30-60 cm of storm snow added a significant additional load to the snowpack, with strong winds contributing to the formation of slabs. These will remain reactive in the short term and can be found on all aspects at treeline and above.
We continue to see more avalanche activity on Nov 22 interface. These facets are reactive, where a slab exists above them, and seem touchier when they are sitting over a sun or temperature crust.
There is a lot of snow hanging from cliff faces, which can catch people off guard in gullies and extreme terrain and act as a trigger to the widespread slab problems. Elevated winds will keep this problem active through the weekend.
Avalanche control at local ski hills on Saturday produced widespread results up to size 3. These slides failed on a combination of wind and persistent slabs. In addition to widespread explosive-triggered avalanches, ski patrol reported a size 3 vehicle remote avalanche triggered by helicopter rotor wash. The natural avalanche cycle is still active; our field team observed a size 2.5 natural that released on the persistent problem.
30-60cm of storm snow fell last week, accompanied by strong SW winds. Fresh wind slabs are prevalent in the alpine and into treeline up to 60cm deep. 60-80cm of snow sits over a mid-November interface of facets that are particularly touchy when they are associated with a sun or temperature crust that exists in some places well into the alpine. Further down, the November 13 rain crust extends to 2100-2300m.
Southwest flow brings precipitation starting Sunday and continuing into early next week. Lower elevations will see rain/snow mix. Upper elevations are forecast for 20–50 cm of snow. Unseasonably warm temperatures keep the freezing level near 2000m Sunday and Monday. This pulse will be accompanied by strong to extreme southwest winds.
For more info, click here for Environment Canada tables.
