Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Regions
Jasper.
Recent warm days and cool nights have strengthened the mid and upper snowpack, but changes to the deep persistent weakness will be much slower. A conservative approach is warranted.
Weather Forecast
Friday will be cloudy with sunny periods, isolated flurries, trace of snow, Alpine high temperature -7 °C, and wind southwest 15-30 km/h. Saturday will be periods of snow, accumulation 17 cm, Low -8 °C and High -6 °C, wind southwest 30 km/h gusting to 90 km/h. A detailed mountain weather forecast is available from Avalanche Canada.
Snowpack Summary
Surface conditions vary from a thin crust on steep solar aspects, 5-10mm surface hoar in sheltered areas, good powder skiing in sheltered locations, and wind effect in exposed areas from recent moderate-strong SW winds. A generally strong mid snowpack overlies the deep persistent weaknesses of facets and depth-hoar.
Timing, track, or intensity of incoming weather system is uncertain on Saturday
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.