Avalanche Forecast

Archived

Jan 27th, 2023–Jan 28th, 2023

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 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

Jasper, Brazeau, Churchill, Cirrus-Wilson, Fryatt, Icefields, Maligne, Marmot, Miette Lake, Pyramid.

10-20 cm of new snow, and reverse wind loading from the north has arrived. The big drop in temperatures is on it's way.

Avoid exposing yourself to avalanche terrain, and allow the inherently weak snowpack to adjust to all these changes.

Confidence

Moderate

Avalanche Summary

Snowballing and previous loose wet activity was noted on steep west aspects near Weeping Wall.

A large avalanche (sz3) observed Thursday in the Icefields. Started in the alpine, running mid-track on deep facets, well into below treeline.

If you're out in the hills, don't forget to post to the MIN. Every bit of information helps.

Snowpack Summary

10 to 20cm of new snow overlies a melt-freeze crust up to 2000m, and moderate north winds at ridge top are redistributing the new snow in an atypical pattern. This, along with the small increments of snow and the wind slabs formed by strong SW winds over the past week, is all sitting on a generally weak and facetted snowpack. The depth of the snowpack is between 50 and 120cm, with shallow areas being especially weak.

Weather Summary

Cold, clear, and dry weather is in store for the weekend as a surface ridge of high pressure is established over the region.

Detailed weather forecasts from Avalanche Canada: https://avalanche.ca/weather/forecast

Terrain and Travel Advice

Avoid exposure to overhead avalanche terrain, avalanches may run surprisingly far.
Be especially cautious as you transition into wind affected terrain.
Avoid terrain traps such as gullies and cliffs where the consequence of any avalanche could be serious.

Problems

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.

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.

Loose Dry

Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.