Archived

Avalanche Forecast

Feb 15th, 2017–Feb 16th, 2017

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

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

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: Little Yoho.

Tricky conditions - skier triggered size 2.5 today and many large avalanches over the past 4 days. Give avalanche terrain that has not had a large avalanche a wide berth.

Weather Forecast

The temperatures will drop through the day on Thursday and will be accompanied by some more new snow (5 cm probably thursday night).

Snowpack Summary

45 cm of settled snow has formed a cohesive slab overlying a series of weak layers. Test results indicate "sudden" shear failures on these layers, which indicates that they are primed for triggering. Recent strong winds and warm temperatures have tipped the balance, and most slopes that have not avalanche should be considered highly suspect.

Avalanche Summary

Skier triggered a size 2.5 avalanche on West aspect, in Lipalian 2 outside Lake Louise ski area. Numerous large deep avalanches over the past 4 days. Avalanche control on Tuesday produced an impressive size 3 avalanche on Vermillion Peak.

Confidence

Avalanche Problems

Wind Slabs

Strong to extreme winds from the SW have created wind slabs and fragile cornices that are ripe for triggering. Give avalanche terrain a wide berth and remember that fracture lines may extend further that you expect with hard slabs in alpine areas.

If triggered the storm/wind slabs may step down to deeper layers resulting in large avalanches.
Pay attention to overhead hazards like cornices which could easily trigger persistent slabs.

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

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 3

Persistent Slabs

The recent snow has created a touchy slab over the weak facets at all elevations. Avalanches that have run full path have been observed in many areas.

Use conservative route selection, choose moderate angled and supported terrain with low consequence.
Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible - Likely

Expected Size: 2 - 3