Avalanche Forecast

Archived

Nov 16th, 2023–Nov 17th, 2023

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Early Season

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Early Season

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Early Season

Regions

Kananaskis, Bow Valley, Highwood Pass, North 40, Spray - KLakes.

Wind slabs are sensitive to avalanche triggering. Be conservative in route selection.

Confidence

Low

Avalanche Summary

Report on Thursday of one skier remote size 2 and one avalanche sympathetic size 2 avalanches, both near Burstall Pass at 2500m on an East aspect. Both avalanches failed on basal facets underneath a buried wind slab.

Snowpack Summary

Another 10cm of new snow fell on Wednesday night which brings this weeks snowfall amounts near 30cm. The theme for the snowpack this week is wind slabs overlying the November 10 crust and facets. This week's storm snow has seen 2 significant wind events that have created reactive wind slabs in the alpine. These wind slabs are sitting on either a slippery crust and/or facets that are both creating the sliding layer for the recent avalanches. Total snow varies from 20-70cm. Coverage is very inconsistent with LOTS of hidden hazards.

Weather Summary

Warming trend for Friday with freezing level rising up to 2700m. Mostly sunny with some clouds and 30-40km/h winds from the West.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Be carefull with sluffing in steep terrain, especially above cliffs and terrain traps.
Avoid lee and cross-loaded terrain.
Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
Avoid terrain traps where the consequence of any avalanche could be serious.

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.

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.