Archived

Avalanche Forecast

Feb 7th, 2018–Feb 8th, 2018

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

3: Considerable

The avalanche danger rating below treeline will be considerable

Alpine

4: High

The avalanche danger rating in the alpine will be high

Treeline

4: High

The avalanche danger rating at treeline will be high

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: Glacier.

The Pacific storm is bringing heavy snowfall between this morning and Thursday evening. Limit exposure to overhead avalanche hazard. Make conservative terrain choices!

Weather Forecast

A winter storm is upon us and is forecast to bring us 40cm+ of snow by the end of the day Thursday. The main pulse should occur Wednesday night into Thursday morning. Moderate to strong SW winds and rising freezing level to 1500m will prime the surface layers with wind and storm slab formation.

Snowpack Summary

A winter storm is potentially bring us 40cm+ snow by Thursday evening. Previous strong S'ly winds created wind slabs in the alpine and exposed areas at TL. These slabs are now buried under fresh storm slab formations. Recent observations showed failures at these interfaces, with potential to step down to our plethora of persistent weak layers.

Avalanche Summary

Several naturals in the HWY corridor Monday up to size 3. Only three new slides observed in the corridor Tuesday. On McGill Shoulder Monday there was a skier accidental size 2, 30-50cm deep, 50m wide and ran for 300m in length. Significant sluffing was also observed in the Bostock drainage.

Confidence

Forecast snowfall amounts are uncertain

Avalanche Problems

Storm Slabs

40cm new snow and mod winds, our storm slab is not getting time to heal. A layer of large stellars was found down 25cm Monday, which could have been the culprit layer in regards to the size 2 skier accidental slide reported Monday on McGill.

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

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Likely - Very Likely

Expected Size: 1 - 3

Persistent Slabs

The Jan 16th, 4th and Dec 15th surface hoar layers have been quiet recently but may reawaken given a large trigger such as a storm slab avalanche or cornice fall.

Pay attention to overhead hazards like cornices which could easily trigger the deep persistent slab.Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible

Expected Size: 1.5 - 3.5

Loose Dry

Rapid snowfall on top of the 20cm+ already received this week will prime the surface for sluffing. Both natural and skier triggered sluffing can be expected today.

The new snow will require several days to settle and stabilize.Use caution above cliffs where small avalanches may have severe consequences.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Likely

Expected Size: 1 - 2