Avalanche Forecast

Archived

Dec 8th, 2022–Dec 9th, 2022

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.

Forecasters had lots of settlements on Thursday at the treeline area indicating that a skiers weight can trigger an avalanche. Any avalanche is likely to step down to the deeper weak facetted base.

Confidence

High

Avalanche Summary

No new avalanches were observed on Thursday but visibility was limited due to light snowfall and low cloud.

Snowpack Summary

A few slab avalanches (both human and naturally triggered) in steeper terrain have been noted in recent days. As the winds increase on Thursday, we expect windslabs to become more widespread on lee aspects (N and E).

The basal layers of the snowpack are typical of the eastern Rockies for this time of year, and consist almost entirely of facets. Unfortunately this condition is not going anywhere fast, and may be with us for the season. Any avalanche that initiates in the upper snowpack is likely to fail in the deeper weak facets and involve the intire snowpack.

Weather Summary

Winds will decrease overnight and be more moderate on Friday out of the SW. Light snow will continue with daytime high around -10C. This weather pattern should be expected to persist throughout the weekend.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
Be especially cautious as you transition into wind affected terrain.

Problems

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.

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.