Avalanche Forecast

Archived

Jan 16th, 2024–Jan 17th, 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.

It felt tropical on Tuesday with -10s in the Alpine! 10cm of new snow over the next few days adding load to the previous windslabs that exist along ridgelines and gullies. Good skiing in sheltered areas at treeline and above but below treeline, be prepared for logs and barely buried hazards.

Confidence

High

Avalanche Summary

A few loose dry sluffs from steep terrain as well as one sz 1 wind slab in Tent bowl that only involved the upper snowpack.

Snowpack Summary

The cooler temperatures over the previous week have facetted out the upper snowpack leaving it feeling low density on the top 10cm. As soon as you approach treeline features though, windslabs become more apparent along ridgelines and in gullied terrain. These slabs had a "cakey" feel on Tuesday in the Tent ridge area but there wasn't any cracking or whumpfing noted. Deeper in the snowpack the Dec 5th crust is being found up to 2350m with weak facets and depth hoar below this layer. Thin areas are places a skier may be able to trigger a failure in these basal facets that can propagate across a feature. Continue to check the depth of the snow as you travel feeling into the snowpack for the hard over soft feeling (Crust over basal facets). In below treeline areas, the snowpack is generally shallow with lots of logs and alders present.

Weather Summary

The deep freeze is over! Well it felt over at -13C!! Overnight and throughout the day on Wednesday we are expecting around 5-15cm with generally light winds. Temperatures will be around -20C in the am warming up to -14C.

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.
Watch for rapidly changing conditions during periods of heavy loading from new snow, wind, or rain.

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.