Avalanche Forecast

Archived

Dec 30th, 2024–Dec 31st, 2024

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, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

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

Deep persistent slabs remain the primary avalanche concern.

Better skiing conditions and a more supportive snowpack can be found in the alpine on solar aspects.

Be mindful of thick to thin transitions within the snowpack where deeper instabilities are more likely to be triggered.

Confidence

Moderate

Avalanche Summary

The local ski hill reported triggering of the deep persistent slab during control work. No other recent avalanche activity observed since December 27 when a size 1 and size 2 were observed in steep, rocky terrain.

Snowpack Summary

The snowpack is mostly made up of facets and ranges in depth from 60 to 120 cm at treeline and above. At the bottom of the snowpack there are multiple early season crusts with facets above and below.

Weather Summary

Mainly cloudy skies with a trace to 5 cm of snow, light to moderate winds out of the NW, and a cooling trend, is expected between now and Wednesday.

Terrain and Travel Advice

Be careful as you transition into wind-affected terrain.
Avoid shallow, rocky areas where the snowpack transitions from thick to thin.

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.