Avalanche Forecast

Archived

Dec 23rd, 2025–Dec 24th, 2025

Alpine

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 unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Regions

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

Natural avalanche activity has tapered off somewhat, but a few very large natural and human-triggered slides have occurred. Large and destructive avalanches are possible. It is time for conservative terrain choices! Great skiing is found in sheltered areas below treeline.

Confidence

Avalanche Summary

A naturally triggered size 2.5 was observed today in the Hero's Knob area in steep Alpine terrain on an East aspect. The slide looks to be less than 24hrs old and had a fracture line of approximately 150cm deep.

A significant remote triggered large avalanche (reported as size 3.5) occurred Monday in the Black Prince zone. Thanks to those that posted a MIN of this event. This avalanche was very deep and likely ran on the Nov crust layers.

One size 2.5 naturally triggered persistent slab was observed in the Burstall Pass area on Sunday. The avalanche exhibited very wide propagation (250m), but did not run far down slope. The slide was also very deep in some parts of the crown, ranging from 100 to 300cm deep.

Snowpack Summary

Another 2 to 5cm of snow fell in the last 24hrs, bringing the recent storm snow up to as much as 100cm in the past week. Unfortunately the winds have been strong throughout this period. Wind slabs are widespread in the alpine and on lee and cross-loaded features at treeline. These wind slabs are likely to be sensitive to skier traffic. The December 16th crust is down about 75cm, but isn't producing shears. The November crust is now down 100-150cm, and is showing signs of faceting. Any avalanche triggered in the upper snowpack has a strong likelihood to step down to deeper instabilities.

Weather Summary

Christmas Eve should bring another cloudy day with light snow. Between 5 and 10cm are possible with moderate SW winds midday increasing to extreme winds (100km/h) by evening. Temperatures will be very mild, with a high of 0 Celsius and freezing levels near 2200m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
Be careful as you transition into wind-affected terrain.
Avoid areas with overhead hazard.
Fresh snow rests on a problematic persistent slab, don't let good riding lure you into complacency.

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.