Archived

Avalanche Forecast

Nov 20th, 2015–Nov 21st, 2015

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

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

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

3: Considerable

The avalanche danger rating below treeline will be considerable

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

Regions: Jasper.

Winds will increase moderate to strong WNW Saturday afternoon. With the storm snow still available for transport, this may be the weather that tips the scales to forming widespread windslab conditions. Be vigilant.

Weather Forecast

Expect seasonal temperatures next few days with a slight warming trend Saturday. A wind event may occur Saturday afternoon into Sunday bringing moderate to strong WNW winds. Monday may bring 20-30cm of storm snow. Be observant the impacts of wind transport and resulting slab development.

Snowpack Summary

Profile at Parkers study plot at treeline 2000m had 90cm snowpack. Top 30cm is low density recent storm snow over slightly more dense midpack. Foot penetration is 50cm. In the field, snow depths vary between 70 to 140 cm in the Icefields. Unsupportive conditions persist below treeline and improve with elevation. Wind slabs forming on lee aspects.

Avalanche Summary

Explosive work on Parkers slabs on Wednesday produced avalanches up to size 2.5. Friday's patrol revealed no new avalanches and visibility was excellent.

Confidence

Wind speed and direction is uncertain on Saturday

Avalanche Problems

Wind Slabs

After the storm, northerly alpine winds reverse loaded lee aspects. Strong winds since yesterday have been forming new wind slabs on lee aspect slopes. These slabs are sitting on a weakness at the ground, full depth avalanches are possible.

If triggered the storm/wind slabs may step down to deeper layers resulting in large avalanches.Be cautious as you transition into wind affected terrain.

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 3

Loose Dry

50-70 cm of unconsolidated snow is sitting on steep terrain. Expect point releases from cliffs and steep smooth surfaces. Wind, sun and other triggers could release this snow and be enough mass to bury a person or push an ice climber off.

Be cautious of sluffing in steep terrain.Be very cautious with gully features.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 1 - 2