Avalanche Forecast

Archived

Dec 31st, 2024–Jan 1st, 2025

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.

Happy New Year!!

May your resolution (to find the good skiing in sheltered areas) include caution around lingering wind slabs, and the possibility of triggering full depth avalanches. We will unfortunately be bringing our weak snowpack with us into the new year.

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

Up to 10cm of new snow has fallen with generally very light winds.

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

Accumulations of 5-10 cm by Wednesday are expected. Flurries and cloudy skies will give way slightly, and temperatures will plummet to around -20 to -25, by Thursday this week. All week, expect light westerly ridgetop winds.

Terrain and Travel Advice

Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
Be careful as you transition into wind-affected terrain.
Wind slabs are isolated, but may remain reactive.

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.