Avalanche Forecast

Archived

Jan 27th, 2024–Jan 28th, 2024

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Regions

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

Freezing levels keep slowly creeping upwards. A increase in avalanche activity is expected. Keep an eye out for decreasing stability in the surface snow, such as snow balling and pinwheeling.

Confidence

Moderate

Avalanche Summary

Nothing new has been reported or observed.

Snowpack Summary

The surface snow in the valley bottoms are starting to become moist during the warmth of the day. The top 30cm of the snowpack is either made up of settled snow or wind slabs and is overlying 5-15cm of facets. These wind slabs were found at treeline and above and produced some cracking when travelling uphill. The January 8th facet/crust surface hoar layer is down about 25-30cm and is getting better as the warmth sinks in.

Weather Summary

Sunday will continue with the warm temperatures, Freezing levels will continue to slowly rise to 2100m Ridge winds 55km/h out of the West. Cloudy skies. Freezing rain is talked about on some models.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
Be carefull around freshly wind loaded features.
In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.

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.

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.