Archived

Avalanche Forecast

Nov 27th, 2022–Nov 28th, 2022

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

1: Low

The avalanche danger rating at treeline will be low

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

1: Low

The avalanche danger rating at treeline will be low

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

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

Uncertainty remains with how the new snow will contribute to the likelihood of triggering persistent slabs, that were already overlying a weak base.

Confidence

Moderate

Avalanche Summary

Lake Louise ski area triggered a size 1.5 wind slab with explosives in a high alpine lee pocket. Otherwise no avalanches were observed or reported.

Snowpack Summary

Up to 20cm of new snow has accumulated in the last 3 days, less so in valley bottoms. Windy conditions has promoted wind slab development in the alpine. The snowpack below these slabs is a mix of facets, spotty surface hoar, and sun crust on steep south aspects. 40-80 cm of total snow exists at treeline throughout the region, with up to 120 cm in loaded alpine features.

Weather Summary

Dropping temperatures and clearing skies into Monday. -20 at the ridge and -15 in valley are expected. The wind will also decrease into the light range from the North.

https://avalanche.ca/weather/forecast

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Fresh snow rests on a problematic persistent slab, don't let good riding lure you into complacency.

Avalanche Problems

Persistent Slabs

Slabs overly weak facets (and even some depth hoar) in most areas, as well as suncrusts and surface hoar in isolated locations.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1.5 - 2.5

Wind Slabs

Up to 20cm of new snow distributed by strong winds has created thin soft slabs. Many of these sit on older wind pressed surfaces.

Aspects: North, North East, East, South East, South, North West.

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 1.5

Loose Dry

New snow and wind input on Sunday will promote loose dry avalanches. This is mainly a problem for ice climbers and skiers in steep, gullied terrain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible

Expected Size: 1 - 1.5