Avalanche Forecast

Archived

Dec 12th, 2024–Dec 13th, 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, 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.

Windslabs persist in leeward slopes. Sheltered areas may offer the best chance for finding soft turns,

Multiple crusts from earlier in the season are still present near the bottom of the snowpack and have the potential to be unstable. Consider digging down and having a look in the area you are skiing or riding in.

Confidence

High

Avalanche Summary

One natural size 2 avalanche, failing on the early season crust, and two natural size 2 windslabs were observed on alpine southwest and south aspects on Monday, December 9th near the Icefields.

Snowpack Summary

Throughout the week moderate to strong winds at treeline and above have redistributed up to 20cm of snow into windslabs. There is a surface hoar layer that has been found in sheltered Alpine areas down 40-60 cm's. At the bottom of the snowpack there are a variety of early season crusts with large faceted crystals above and below. Both of these layers have been producing sudden planar, compression test results in test profiles.

Weather Summary

Friday:

Cloudy with isolated flurries, accumulating a trace of snow. Alpine temperature high of -6 °C. Ridge wind from the southwest 15-25 km/h. Freezing level at valley bottom.

Saturday

Saturday:

Flurries could see accumulation up to 6 cm. Alpine temperature low of -10 °C and a high -6 °C. Ridge wind from the southwest 15 km/h gusting to 45 km/h. Freezing level at valley bottom.

Sunday

Sunday:

Cloudy with sunny periods and isolated flurries accumulating a trace of snow. Alpine temperature: low of-14 °C and a high of -9 °C. Mostly light ridge wind occasionally gusting to 45 km/h. Freezing level at valley bottom.

Terrain and Travel Advice

Be mindful that deep instabilities are still present in the snowpack.
Be careful as you transition into wind-affected terrain.

Problems

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.

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.