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.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Regions
Jasper.
Over 100cm of snow has fallen in the Ice Fields region since Dec 11. We continue to see wide spread avalanche activity throughout the back country. This is the time to be on high alert when traveling in any avalanche terrain.
Weather Forecast
A cooling trend has taken hold. Temperatures will gradually "warm", through the weekend with alpine highs near -10C. The sky will be generally a mix of sun and cloud with no precipitation in the near future. Moderate south-west winds forecastedA detailed mountain weather forecast is available from Avalanche Canada.
Snowpack Summary
Moderate south west winds continue to load lee slopes at tree line and above. The Dec. 11th persistent weak layer has been buried by up to 100cm snow and producing a significant natural cycle up to size 4, observable from the Icefields Parkway . The deep persistent weakness lingers near the ground.
Avalanche Summary
Friday's avalanche control produced consistent size 2 to 2.5 avalanches running to roadside. Damage from the most recent, intensive natural cycle is only now visible; with large slides, on skied terrain. Most notably is a large, possibly cornice triggered size 3.5, which ran nearly full run-out, on the Churchill (north and south) slide paths.
Confidence
Due to the number and quality of field observations
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.
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.