Avalanche Forecast

Archived

Dec 6th, 2023–Dec 7th, 2023

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Regions

Jasper, Brazeau, Churchill, Cirrus-Wilson, Icefields.

An avalanche cycle is happening with new storm snow overlaying a generally weak faceted snowpack. Make conservative decisions until the new snow has had time to settle and stabilize.

Good skiing is out there but the threat of early season hazards is real and just below the surface. Read a recent report from Parkers here.

Confidence

Moderate

Avalanche Summary

Numerous storm slab avalanches released during Tuesday's storm, failing on the Dec 2 surface hoar, facet and melt-freeze crust layer.

More information on a size 1.5 near Parkers ridge behind Hilda hostel can be found here (Here).

Snowpack Summary

30cm of new snow redistributed by strong winds has formed windslabs and storm slabs. This overlies a weak surface hoar and facet layer or a melt-freeze crust on south and west aspects. The snowpack is 35-45cm in depth with a weak base.

A rain crust exists below 1800m.

Weather Summary

The Mountain Weather Forecast is available from Avalanche Canada https://avalanche.ca/weather/forecast

Thursday

Cloudy with sunny periods and light ridgetop winds. Alpine temperature: High -8 °C. Freezing level at valley bottom.

Terrain and Travel Advice

Continue to make conservative terrain choices while the storm snow settles and stabilizes.
Keep your guard up at lower elevations. Storms slabs have been reactive at all elevations.
Don't let the desire for deep powder pull you into high consequence terrain.

Problems

Storm Slabs

Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.

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.