Avalanche Forecast

Archived

Dec 22nd, 2025–Dec 23rd, 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.

Extensive wind loading has occurred and slopes appear primed for human triggering at treeline and above. Conservative terrain choices are crucial. Good skiing in protected areas below treeline.

Confidence

Avalanche Summary

One size 2.5 persistent slab was observed in the Burstall Pass area today. The avalanche looked to be about 24hrs old and 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

The snow keeps coming! Another 10cm in the past 24hrs, brings recent storm snow up to as much as 90cm. 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

Tuesday will be cloudy with temps near -7C for a high. Snowfall amounts are expected to be in the 5-10cm range. Unfortunately the winds will be out of the SW at 100km/h to start the day, and then decrease somewhat by midday.

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.

Persistent Slabs

Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.