Avalanche Forecast

Archived

Dec 14th, 2023–Dec 15th, 2023

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.

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.

The wind is forecast to increase through Friday. Watch for new wind-slabs and spin drift avalanches if ice climbing or skiing.

Confidence

High

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

Trace amounts of snow fell on Thursday. The snowpack is 40-60cm deep and is weak and facetted. A surface hoar layer is down 15-20cm below 2300m. Previous 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

Friday

Mainly cloudy with isolated flurries.

Precipitation: Trace.

Alpine temperature: High -6 °C.

Ridge wind southwest: 20 km/h.

Saturday

Mainly cloudy with isolated flurries.

Precipitation: Trace.

Alpine temperature: Low -7 °C, High -5 °C.

Ridge wind west: 20-30 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.