Avalanche Forecast

Archived

Dec 1st, 2024–Dec 2nd, 2024

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 unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

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

Wind slabs are evident at upper elevations. Use caution when entering lee and cross-loaded terrain, and be aware of overhead terrain.

Confidence

Moderate

Avalanche Summary

No new avalanches were observed on Sunday, but field teams on Saturday reported significant sluffing in steep cliffy terrain, mainly on East aspects. This was likely due to the strong wind event that was occurring at the time. A party reported a near miss from an overhead avalanche near Tryst Ridge/Little Tent Ridge - see the MIN.

Snowpack Summary

Extensive winds over the previous couple of days have created widespread winds slabs at 2300m and above. Not much evidence of natural avalanche activity on this problem yet, but human triggering on lee and cross-loaded slopes is likely. At lower elevations the snowpack remains weak and unconsolidated with many early season hazards lurking. The October rain crust is one to watch. It is now buried 40 to 70cm and would provide a good sliding layer if the layer above was triggered.

Weather Summary

Monday will be mainly sunny with high temp near -4C. Winds will be moderate to strong from the W to NW. No snowfall is expected for the next several days.

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.

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.