The annual rotting of the snowpack is in full effect. As this happens watch for areas that still have a slab sitting over facets.
Weather Forecast
Another cold night in the forecast with AM temperatures (-15 to -20C) but inverted in the alpine (-5 to -10C). SW winds will increase into the moderate range Saturday afternoon into Sunday. A warming trend will continue through to Monday with no real snow in the forecast....
Snowpack Summary
No new snow in several days. Thin wind slabs in immediate lee areas at treeline and above. The October 26th crust/facet layer is ~30 cm above ground. In many areas the entire snowpack is faceting and becoming quite weak. Snow depths range from 50-85 cm at 2000 m.
Avalanche Summary
A skier accidental was reported Wednesday on the slopes skiers left of Bow Summit. It was a size 1.5 and likely failed on the Oct 26th crust/facets. Additionally some small thin wind slabs were reported in the Observation Peak and Sunshine Village areas. A few small loose dry avalanche have also been observed.
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.