Archived

Avalanche Forecast

Dec 5th, 2023–Dec 6th, 2023

Alpine

4: High

The avalanche danger rating in the alpine will be high

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

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

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

An avalanche cycle is happening with heavy wet storm snow overlaying a generally weak faceted snowpack. Skiers should be choosing conservative terrain. Ice-climbers should be picking routes with no over-head hazard.

Confidence

Moderate

Avalanche Summary

Numerous natural avalanches up to size 2 were reported on Tuesday running as storm slabs and deep persistent slabs at all elevations. Widespread whumphing and cracking was reported in areas not steep enough to avalanche.

Snowpack Summary

Up to 35 cm of moist storm snow overlays well developed surface hoar, faceted snow, and sun-crusts on steep south aspects. Previous strong SW winds have formed windslabs in alpine and tree-line locations. The mid and lower pack is generally weak and faceted. Snow depths range from 40-60 cm at tree-line and up to 90 cm in deeper alpine locations.

Weather Summary

A continued SW flow will bring more snow to the forecast area on Wednesday with another 20 cm possible by the evening. Freezing levels will hover around 1300m then lower to valley bottom on Thursday. Winds should taper through the day on Wednesday and switch from SW to W.

For more information click Mountain Weather Forecast.

Terrain and Travel Advice

Storm slabs in motion may step down to deeper layers resulting in large avalanches.
Avoid exposure to overhead avalanche terrain, avalanches may run surprisingly far.

Avalanche Problems

Storm Slabs

Up to 35cm of heavy wet storm snow is sitting on a weak faceted snowpack and may become more reactive as it settles.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Very Likely - Certain

Expected Size: 1 - 2

Deep Persistent Slabs

The mid and lower pack are thin and faceted in most areas. Surface avalanches could scrub down to the facets resulting in a full depth avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Very Likely - Certain

Expected Size: 1 - 2