Avalanche Forecast

Archived

Dec 29th, 2025–Dec 30th, 2025

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

Kananaskis, Bow Valley, Highwood Pass, North 40, Spray - KLakes.

The strong winds continue to redistribute recent snow, building widespread wind slabs on most aspects. Natural avalanche activity has tapered, but cautious route selection is advised as you transition into wind effected snow. Also be mindful of overhead hazard.

Confidence

Avalanche Summary

Several naturally triggered wind slabs up to size 2.5 have occurred in the past 48hrs on South, East and North aspects in Alpine and Treeline elevation bands. These slabs range from 30 to 100cm deep.

Avalanche control in the past few days has consistently triggered wind slabs up to size 2.0 in Alpine terrain.

Snowpack Summary

Wind slabs are widespread in the Alpine and open areas at treeline. Although natural avalanche activity has tapered, many areas are prime for human-triggering. The recent storm snow is settling at lower elevations, but sheltered areas still have great skiing. The Nov crust layers are buried 120 to 180cm and are beginning to facet. Some recent avalanches have stepped down to the Nov crust, but this has recently been more common in shallow snowpack areas.

Weather Summary

Tuesday will be a mix of sun and cloud with high tempos near -3C. Winds will start the day near 60km/h from the SW and increase to almost 100km/h. No precip is expected.

https://hpfx.collab.science.gc.ca/~fsg006/productviewer/ab/table/AB_Rockies_Forecast.html

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Watch for newly formed and reactive wind slabs as you transition into wind-affected terrain.
If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
Be mindful that deep instabilities are still present and have produced recent large avalanches.
Keep in mind that human triggering may persist as natural avalanches taper off.

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.