Avalanche Forecast

Archived

Jan 8th, 2024–Jan 9th, 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, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

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

Lots of wind in the past 24 hours (including reverse wind loading) has formed wind slabs at upper elevations. Most weather models are not calling for much snow, but if the region gets more snow than expected, hazard levels could rise. Keep an eye on localized conditions.

Confidence

Moderate

Avalanche Summary

Observations were limited today, but small sluffs were observed in the Alpine in extreme terrain due to the on going strong winds.

Snowpack Summary

Recent snow accumulations of up to 15cm is being re-distributed by strong and variable winds at ridgetop. Expect wind slabs averaging 30cm thick on virtually all aspects in the Alpine terrain, and these do extend down into Treeline elevations in some areas. The reactivity of these wind slabs depends on the previous surface they have formed on. In areas where a buried crust exists, or a layer of weak facets, these new wind slabs will be more touchy. At Treeline and below the early December rain crust remains supportive for the most part. Unfortunately the incoming cold snap may start to change that. Otherwise the basal facets and depth hoar remain unchanged.

Weather Summary

Tuesday will be relatively seasonal and then its going to get ugly!

Tuesday will be overcast with scattered flurries and accumulations between 1 and 5cm (although some models say up to 15cm). Winds will be strong to extreme from the SW in the morning, and then decrease in the afternoon. Temperatures should reach -8C.

Then the deep freeze begins. Wednesday will see temps drop through the day into the -25 range, and then as cold as -38 on Thursday morning. Ugh.

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.
Be carefull around freshly wind loaded features.
Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
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.