Avalanche Forecast

Archived

Dec 17th, 2023–Dec 18th, 2023

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

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

Natural avalanches are unlikely but human triggered avalanches are still possible. Alpine wind loaded features should be approached with caution.As temperatures rise above zero in the lower elevations, ice climbers should watch for overhead hazards in form of loose wet/dry sluffs or a rock fall.

Confidence

Moderate

Avalanche Summary

Few small wind slabs observed in the last few days across the region. These slabs were found near ridge tops on northerly aspects and did not step down to deeper instabilities.

Snowpack Summary

The snowpack is 50-80cm deep and is weak and facetted. A surface hoar layer is down 15-20cm below 2300m. Strong winds have stripped exposed alpine and tree-line terrain and created wind-slabs in cross-loaded and lee features. Windward slopes are either stripped of snow or the snow left has been pressed into sastrugi.

Weather Summary

The Mountain Weather Forecast is available at Avalanche Canada https://avalanche.ca/weather/forecast

MondayCloudy with scattered flurries. Accumulation: 4 cm. Alpine temperature: High -2 °C. Ridge wind southwest: 10-30 km/h. Freezing level: 1900 metres.

Terrain and Travel Advice

Avoid areas where the snow feels stiff and/or slabby.
Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.

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.