Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Regions
Little Yoho.
While natural activity has dropped off, human triggering of a large slab avalanche on the deep persistent layer is a possibility. Remain conservative with terrain selection in thin snowpack areas.
Weather Forecast
Temperatures will continue to cool through to Tuesday morning to -10C to -15C values at treeline. A weak system will bring modest amounts of snow beginning Monday night with winds increasing to strong in the alpine Tuesday as temperatures climb back to -5 to -10 values at treeline. Cloud and light snow is forecast to continue through Thursday.
Snowpack Summary
5 to 15 cm of recent snow buried suncrusts and some surface hoar. Moderate to Strong SW winds created small soft winslabs in the alpine Friday and Saturday. Of greatest concern are the weak facets and depth hoar in the lower half of the snowpack. In thin snowpack areas (150cm or less) triggering a slab over this layer is more likely.
Avalanche Summary
Very little natural activity has been observed over that last week. A party in the Emerald Lake area triggered a slab during Saturday's storm in lee alpine terrain. Avalanche Control workers at the ski hills have been working with small soft windslabs for the last two days. We have entered a low likelihood, high consequence period for avalanches.
Confidence
Problems
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.