Avalanche Forecast

Archived

Feb 1st, 2023–Feb 2nd, 2023

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.

Well lets hope for some snow before Valentines day, that gives us two weeks to prepare! In the meantime keep watch for thin areas where the weak base could be triggerred causing a large avalanche. Windslabs are being encountered in alpine areas.

Confidence

Moderate

Avalanche Summary

Nothing new was observed or reported.

Snowpack Summary

Well its hard to talk about last weeks small snow amounts still! 5-10cm of snow is overlying a thin crust from the previous warm temperatures. This crust is just thick enough for you to break through and make the skiing poor....

Watch for windslabs in alpine areas in the upper snowpack making thin weak spots harder to spot. Where the snowpack is thin these are the places wherein a skier may trigger the weak basal facets. As the snowpack above the weaker base has become more cohesive the potential for wide propagation increases. This will be a common theme this winter and you should always be thinking about consequences of an avalanche. Wind slabs may also cause the weak base to fail. Its a tough snowpack this year and unfortunately, it isn't likely to change much this season.

Ice climbers in the Ghost and front ranges should watch for pockets of windslabs along routes that may be triggered.

Weather Summary

Wednesdays temperatures will be in the -10c range with winds increasing to strong by mid-day. There may be a few isolated flurries along the Spray lakes road overnight but accumulations are minimal.

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 aware of the potential for surprisingly large avalanches due to deeply buried weak layers.
If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.

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.