Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Regions
Purcells.
Confidence
Fair - Due to limited field observations
Weather Forecast
A weak system will cross the region in the evening Thursday bringing flurries and light North West winds becoming moderate from the South West later. Temperatures will stay cool for the entire period. Similar conditions are expected for Friday and Saturday except for the winds turning back and forth from the North West to South West and staying light for the rest of the period.
Avalanche Summary
No new natural or skier triggered avalanche was reported recently except for explosive results up to size 2 that ran on West and North West aspects down 40-80 cm on facets. Check out this avalanche report from the Kicking Horse backcountry.from December 10th.
Snowpack Summary
The 5-10 cm of new snow that fell in the past couple days is sitting on the older storm snow and is continuing to settle. Some isolated windslabs exist in the alpine and at treeline on Easterly aspects and on cross loaded features. This loads 2 surface hoar and/or facet layers that were buried at mid November and then, at the end of November. Except for explosive results, recent snowpack tests gave no significant results on these weaknesses located consecutively around 50 cm and 100 cm below the surface of the snowpack. Near the base of the snowpack is the early November crust/facet deep persistent weakness. It would be possible to trigger if you hit the right spot, like a thinner snowpack area on a slope with smooth ground cover.
Problems
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.
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.
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.