Archived

Avalanche Forecast

Jan 28th, 2023–Jan 29th, 2023

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

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

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.

Arctic air and wind chill will persist over the next couple of days. Expect fresh wind slab development with incoming strong North winds.

Confidence

Moderate

Avalanche Summary

Forecasters at the Ogden benches Saturday saw evidence of wind slab activity out of the steep face on Mt. Ogden, with a size 2 stepping down to a deeper weak layer. Those were probably 48 hours old. Another team at observation peak saw a size 2, deeper release which was likely over 48 hours old. Lake Louise ski hill got many size 1-1.5 wind slab avalanches with explosive control.

Snowpack Summary

5-10cm of new snow over the past couple of days is being blown into wind slabs at treeline and in the alpine. Below this, the upper snowpack contains weak layers 20-40 cm deep (Jan. 4th) and 30-60 cm deep (Dec. 17th) that are generally unreactive. The Nov 16 deep persistent layer is down 40-90 cm and continues to produce variable test results. In areas west of the divide, these layers are generally deeper and more spread apart in the snowpack.

Weather Summary

On Sunday, expect North winds 50-60km/h diminishing to 30km/h and -20C to -25C. Continued cold temperatures on Monday then slowly warming through the week.

Terrain and Travel Advice

Uncertainty is best managed through conservative terrain choices at this time.
Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.

Avalanche Problems

Wind Slabs

A combination of new snow and moderate winds have formed new wind slabs in the alpine. Forecast strong alpine wind values will likely increase this problem over the short term.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 1.5

Deep Persistent Slabs

The lower snowpack is comprised of weak facets and depth hoar with the upper snowpack forming a 40 to 90cm thick slab above. Not much has changed with this layer.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2.5