Avalanche Forecast

Archived

Jan 15th, 2024–Jan 16th, 2024

Alpine

Natural avalanches unlikely, human triggered possible.

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.

Tuesday will finally bring a change. Temperatures will moderate, winds will shift to the SW in the afternoon and light flurries will begin. Approach the alpine with the possibility that wind slabs are present. Good skiing can be found in sheltered areas.

Confidence

Moderate

Avalanche Summary

One naturally triggered size 1.0 slab avalanche was observed in a steep SE facing gully feature at approximately 2300m. This slab was 25cm deep and about 25m wide. The likely trigger was incremental wind loading. Otherwise only a couple of very small sluffs were observed in very steep Alpine terrain.

Snowpack Summary

With the cold weather, the forecasters have only been able to make observations from the road for the last few days. Surface faceting is on-going with the cold temps. Last week's snow came with some wind but the wind slabs have likely broken down some with the cold temperatures. A spotty surface hoar layer down 30-40cm is worth investigating. The December 5th melt/freeze crust is down approximately 50-70cm down and is an important layer to track, especially in shallower snowpack areas. The basal facets will be with us for the season and are mostly a concern for triggering in shallow snowpack areas. Expect good skiing in sheltered areas.

Weather Summary

A reprieve from the cold is finally coming! It will be "only" -23C overnight, and then a balmy -11C for a high on Tuesday. Somewhere around noon the winds will shift from the NW to the SW, bringing with it a few flurries. Up to 5cm will fall Tuesday afternoon/evening with another 10cm through the day on Wednesday.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Recent wind has varied in direction so watch for wind slabs on all aspects.
In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.

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.