Avalanche Forecast

Archived

Dec 13th, 2023–Dec 14th, 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 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.

Snow is forecast to fall through Thursday. Before committing to a ski line make sure to test how the snowpack is reacting to this new load and remember there are numerous early season hazards just below the surface.

Confidence

Moderate

Avalanche Summary

A few small wind slabs reported at ridge top at Marmot Basin over the past couple of days. Widespread spin drifts were noted off steep rocky terrain due to the strong winds on Wednesday.

Snowpack Summary

The snowpack is 40-60cm 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.

Weather Summary

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

Thursday

Cloudy with scattered flurries.

Accumulation: 5 cm.

Temperature: High -4 °C.

Ridge wind southwest: 10-25 km/h.

Freezing level: 1700m

Friday

Cloudy with scattered flurries.

Accumulation: 4 cm.

Temperature: Low -9 °C, High -5 °C.

Ridge wind southwest: 20-40 km/h.

Freezing level: 1500m

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.