Avalanche Forecast

Archived

Dec 24th, 2024–Dec 26th, 2024

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.

Below Treeline

Natural avalanches unlikely.

Regions

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

Only a few cm's of snow is forecast for Wednesday and Thursday. The avalanche hazard is expected to remain the same. Look to sheltered northerly aspects for isolated pockets of soft snow.

Confidence

Moderate

Avalanche Summary

No new avalanches have been reported.

Snowpack Summary

We do not expect the snowpack summary to change in the next couple of days given that only 2-8cm is possibly forecast with moderate winds and below freezing temperatures. The recent snowfall is settling rapidly on all but the most sheltered northerly aspects. Wind slabs dominate the Alpine landscape with multiple layers of laminated wind slabs in the upper snowpack. The Dec crust down 30 to 50cm is spotty through the forecast area, but is a layer of concern. The deeper Nov and Oct crusts are faceting and could be triggered with large loads such as a cornice or a surface wind slab. Overall snowpack depths are well below average, and in many lower elevation areas it has little to no strength.

The next avalanche bulletin will be issued in the late afternoon of December 26. If the avalanche hazard is expected to increase before this time, an updated bulletin will be issued.

Weather Summary

Wednesday: Accumulation of snow will be minimal but maybe a few centimeters to whiten things up(3cm). Expect a high temperature of -10c in the alpine with ridgetops winds from the SW in the 30-40km/hr.

Thursday: Maybe another 4cm of snow could come for Boxing day with a high temperature of -6c. Winds are expected to be in the 25-25km/hr at ridgetop.

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.
Approach lee and cross-loaded slopes with caution.

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.