Avalanche Forecast

Archived

Nov 30th, 2023–Dec 1st, 2023

Alpine

Natural avalanches unlikely.

Treeline

Natural avalanches unlikely.

Below Treeline

Early Season

Alpine

Natural avalanches unlikely.

Treeline

Natural avalanches unlikely.

Below Treeline

Early Season

Alpine

Natural avalanches unlikely.

Treeline

Natural avalanches unlikely.

Below Treeline

Early Season

Regions

Banff Yoho Kootenay, Little Yoho, Banff, East Side 93N, Kootenay, Lake Louise, LLSA, Sunshine, West Side 93N, Field.

Concern remains for steep slopes where deeper, wind-loaded pockets have created a dense slab sitting over a weak base.

The snowpack remains very thin for this time of the year.

Early Season Conditions persist.

Confidence

Moderate

Avalanche Summary

No new avalanches have been observed or reported for a couple of days.

Snowpack Summary

Strong westerly winds have redistributed last week's 5-20 cm of storm snow.

Generally, the snowpack is thin and heavily wind-affected. There is a thin sun crust on south and west aspects. While surface hoar is growing, it has been blown away in the alpine.

The bottom of the snowpack consists of weak basal facets and a spotty melt-freeze crust from late October.

The snowpack is 30-50 cm deep at treeline with many areas still below threshold, and up to 90 cm in deeper alpine areas.

Weather Summary

Light flurries continue Friday through Saturday. West winds will pick up Saturday evening reaching the moderate to strong range. Treeline temperatures will range from -12 to -17C.

A frontal system arrives Sunday bringing the potential for increased winds, rising temperatures, and minor snowfall.

Mountain Weather Forecast.

Terrain and Travel Advice

Early season avalanches at any elevation have the potential to be particularly dangerous due to obstacles that are exposed or just below the surface.
Watch for wind-loaded pockets especially around ridgecrest and in extreme 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.