Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches possible, human triggered probable.
Alpine
Natural and human triggered avalanches likely.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches possible, human triggered probable.
Alpine
Natural and human triggered avalanches likely.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches possible, human triggered probable.
Regions
Jasper.
We have a very complicated snowpack that requires a thorough assessment before committing to any avalanche terrain. Large whumphs and shooting cracks were noted on Saturday. Ice climbs with overhead hazard should be avoided until the hazard abates.
Weather Forecast
Monday will be flurries, 8cm of snow, alpine temperature High -5 C and ridge wind southwest 20 km/h gusting to 50 km/h. Tuesday to Wednesday is much the same with potentially 36mm of precipitation from Monday to Wednesday. A detailed mountain weather forecast is available from Avalanche Canada.
Snowpack Summary
New snow on the horizon, following recent storm snow, 60cm since Dec 11th in the Icefields region. New snow has been and will continue to be redistributed by moderate SW winds. This interface, Dec11, overly several weak interfaces such as facets, crusts and isolated surface hoar. The deep persistent weakness still lingers near the ground.
Avalanche Summary
A natural avalanche cycle and subsequent avalanche control work resulted in many slab avalanches up to size 3.5 in the Parkers ridge area on Dec 14th. Saturday's field team toured on Parkers Ridge summer trail (ATES 2) and observed many common signs of instability, like shooting cracks and whumphing.
Confidence
Intensity of incoming weather systems is uncertain on Monday
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.
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.