Avalanche Forecast

Archived

Dec 5th, 2024–Dec 7th, 2024

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.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Regions

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

Temperatures will cool on Friday slightly but the damage is done. Expect there to be a new surface crust on steep solar aspects up to 2200m that will become a critical layer in our developing snowpack. Caution for windslabs in alpine areas. Keep a close eye on temperatures and sun Friday, if it does come out, the overnight freeze at upper elevations has been poor the past few days.

Confidence

Moderate

Avalanche Summary

On Wednesday a sz 2 avalanche occurred over Kidd falls likely triggered by daytime warmth. A loose dry slide also reached valley floor in the King Creek drainage on the approach to the ice climbs.

Snowpack Summary

Warm temperatures over the past few days created moist snow on steep solar aspects up to 2300m. This will become a layer to follow when more snow arrives hopefully this weekend. Wind slabs are present in more specific features in the alpine such as lee features and cross loaded slopes/gullies. The height of snow varies from 40cm of facets to 70cm of more consolidated snow. Early season hazards are all over the place at all elevations. The October crust is close to the ground and has started to break down with facets just above it. This is our layer of concern and would provide a good sliding layer if triggered at the right spot. Thin areas are likely places wherein you could trigger an avalanche right now. These might be at the sides of gullies or edges of slopes. Keep this in mind as you travel!

Weather Summary

Temperatures will cool on Friday with a daytime high of -1C. No new snow is forecast and winds will be just moderate out of the west. See image below.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
Avoid steep terrain that is rocky and thin.
Pay attention to isolated wind affected features in the alpine, as well as cross-loaded features at treeline.

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.

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.