Avalanche Forecast

Archived

Dec 14th, 2024–Dec 15th, 2024

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

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.

Below Treeline

Natural avalanches unlikely.

Regions

Jasper, Brazeau, Churchill, Cirrus-Wilson, Fryatt, Icefields, Maligne, Marmot, Miette Lake, Pyramid.

Winds have increased speed into moderate, gusting strong range, ergo the potential for newly formed pockets of windslabs particularly in Alpine and exposed ridgetop Treeline lee slopes. This has the potential to increase the danger until the impacts of the stronger winds can be ascertained.

Confidence

Moderate

Avalanche Summary

Saturday's Maligne field team reports cracking under skis on lee slopes and no new avalanches. Friday's patrol to Beauty creek did not observe any avalanches but visibility was poor.

Snowpack Summary

Incoming snow will fall during windy conditions, potentially forming a thin but reactive windslab. This may form overtop a surface hoar layer that has been found in sheltered Alpine areas down 40-60 cm's. At the bottom of the snowpack there are a variety of early season crusts with large faceted crystals above and below. Both of these layers have been producing sudden planar, compression test results in test profiles.

Weather Summary

Saturday night will be cloudy, flurries, -9 °C, and 20 gusting 50 km/hr SW winds. Sunday's weather is clouds, sun, flurries, -9 °C, 15-35km/hr SW winds. Monday to Wednesday is similar to Sunday but a few degrees colder overall.

Terrain and Travel Advice

Be mindful that deep instabilities are still present in the snowpack.
Be careful as you transition into wind-affected terrain.

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.