Archived

Avalanche Forecast

Nov 22nd, 2015–Nov 23rd, 2015

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

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

Regions: Glacier.

The Winter Permit System comes into effect tomorrow, Monday November 23. A winter permit is required to enter winter restricted ares.

Weather Forecast

A temperature inversion has set up this morning with cool air in the valley bottom and temperatures approaching zero at ridge top. Skies will clear later this morning as strong to extreme westerly winds push in ahead of an incoming weather system. Moderate snowfall amounts are forecasted for early Monday morning with 15cm by Tuesday.

Snowpack Summary

Recent observations suggest that the ~1m of storm snow is settling and bonding. S-SW winds at treeline and above continue to load lee features, forming deep loaded pockets. Surface hoar layers down ~1m and 1.5m are still a concern but becoming more stubborn and hard to find. On high elevation N/NE aspects, there is a weak facetted base.

Avalanche Summary

No new activity observed.

Confidence

Intensity of incoming weather systems is uncertain

Avalanche Problems

Wind Slabs

Strong SW winds in the last 24 hours have transported the recent storm snow and created wind slabs and significant loading in lee areas. Extra caution should be used when transitioning into wind affected terrain.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 2 - 3

Deep Persistent Slabs

On northerly alpine slopes, snow from early Sept was preserved and facetted forming a basal weakness. During the storm this week avalanches occurred on this layer. This layer was also responsible for a skier triggered size 3.5 avalanche 2 weeks ago.

Avoid shallow snowpack areas where triggering is more likely.

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

Elevations: Alpine.

Likelihood: Possible

Expected Size: 3 - 4