Avalanche Forecast

Archived

Dec 10th, 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.

There is still good skiing to be found in areas sheltered from the wind.

The crust and facet layers at the bottom of the snowpack are still lurking. It's a good time to dig down to them, and see what you are skiing on.

Confidence

High

Avalanche Summary

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

Snowpack Summary

Up to 20 cm recent storm snow fell over the weekend. Moderate to strong winds at treeline and above have redistributed the fresh 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

Wednesday

Cloudy with sunny periods and isolated flurries. Trace amounts of precipitation. Alpine temperature: High -4 °C. Winds at ridgeline 10 km/h from the west.

Thursday

Cloudy with sunny periods. No precipitation. Alpine temperature: Low -9 °C, High -4 °C. Winds at ridgeline 10 km/h from the west.

Friday

Mainly cloudy with isolated flurries. Trace amounts of precipitation. Alpine temperature: Low -11 °C, High -8 °C. Mostly light ridge wind occasionally gusting to 35 km/h.

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.