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 possible, human triggered probable.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches possible, human triggered probable.
Regions
Jasper.
Watch out for building wind slabs and cornices.
Weather Forecast
Friday will be cloudy, no precipitation, Alpine High -7 C, and ridge wind southwest 15 km/h. Saturday will be sun, Alpine temperature low -3 C high -1 C, wind southwest 10 km/h, and freezing level 1900 metres. Temperatures may be warmer than forecasted on Saturday. A detailed mountain weather forecast is available from Avalanche Canada.
Snowpack Summary
Moderate to strong winds and allot of snow available for transport from Jan 2-4th 85cm storm continues to build ridge top wind slabs. Last week's snow is settling into a cohesive layer and is overlying; previous widespread wind effect; the Dec. 11th layer in the mid-snowpack; and a weak facet layer on the ground (particularly weak where shallow).
Avalanche Summary
No new naturals observed on Thursday and visibility was good. To the South of Saskatchewan crossing there continues to be consistent reports of large avalanches. Jan 5th helicopter control produced numerous large avalanches with one on Sunset peak destroying 14 hectares of mature timber.
Confidence
Freezing levels are uncertain on Saturday
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.
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.
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.