Avalanche Forecast

Archived

Dec 5th, 2022–Dec 6th, 2022

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 unlikely, human triggered possible.

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.

Early season conditions still exist throughout the forecast region. Ski with caution as the depth of snow is variable in all areas. Watch for signs of instability such as cracking and whumpfing; there is a persistent weak layer buried 25-30 cm below the surface.

Confidence

Moderate

Avalanche Summary

No new avalanche activity was observed or reported. Public MIN posts and Field teams reporting Nov. surface hoar evidence in sheltered BTL locations.

Snowpack Summary

In the Alpine, previous surface snow has been redistributed by winds from a variety of directions creating pockets of wind slab up to 20 cm thick near ridge top and on cross-loaded features. There is a buried layer down 25-30cm that consists of Surface Hoar, Facets, and Sun Crust. Snow depth ranges from 40-100cm.

Weather Summary

Cloudy with scattered flurries.

Accumulation: 4 cm.

Alpine temperature: High -15 °C.

Ridge wind west: 15-25 km/h.

Freezing level at valley bottom.

Wednesday

A mix of sun and cloud with isolated flurries.

Precipitation: Trace.

Alpine temperature: Low -16 °C, High -13 °C.

Ridge wind southwest: 15 km/h.

Freezing level at valley bottom.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Recent wind has varied in direction so watch for wind slabs on all aspects.
Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.

Problems

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.

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.

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.