Avalanche Forecast

Archived

Feb 5th, 2024–Feb 7th, 2024

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Regions

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

Early season conditions in February! Snowpack heights are extremely low at lower elevations. Some "acceptable" skiing can be found in the Alpine with dust on crust conditions. Travel conditions are generally poor.

Confidence

High

Avalanche Summary

Just a few loose dry naturally triggered avalanches were observed in steep terrain on N aspects today. These slides ranged from size 1 to 1.5.

Snowpack Summary

The recent storm snow is settling and now averages 5 to 15cm over the Feb 3 crust. This crust is supportive to skiers above 2100m and extends at least as high as 2500m. The bond at the storm snow - crust interface is mainly good, except on steep northerly aspects in the alpine. Very isolated wind slab development was observed today in the alpine in wind prone areas.

Weather Summary

Wednesday will be mostly cloudy with temps between -5 and -10. Winds will be light from the SW at ridgetop. Very light flurries will bring only trace amount of new snow.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Wind slabs may be poorly bonded to the underlying crust.
Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
Be carefull with sluffing in steep terrain, especially above cliffs and terrain traps.
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.

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.

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.