Archived

Avalanche Forecast

Feb 13th, 2018–Feb 14th, 2018

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

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

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.

Be wary of what's above you and cognisant of other groups below. Cornices have been failing and skiers have remotely triggered large avalanches in popular areas.

Weather Forecast

Unsettled weather approaches Rogers Pass today, bringing with it flurries, cool temps and strong winds. We can expect only 5cm by 4pm, -10 in the Alpine and SW winds. Most our forecasted snow will fall overnight, strong winds will continue and freezing levels will stay at valley bottom.

Snowpack Summary

80cm of storm snow fell in the last week with above average temperatures and strong winds. Wind slabs are lurking in the alpine and in exposed areas at treeline. Persistent weak layers are now buried 150-200cm in the snowpack. Snow depth of 325cm at treeline. Surface sun crust can be expected on steeper solar aspects.

Avalanche Summary

6 avalanches in the HWY corridor occurred yesterday to size 3. Character ranged from loose dry to cornice failures and persistent slabs. The most notable was a skier remote size 3. Skiers were ascending MacDonald West Shoulder #4, adjacent to NRC Gully, when they remotely triggered a size 3.0. It was 50-120cm deep, 200m wide and ran for 1.6km.

Confidence

Due to the number of field observations

Avalanche Problems

Wind Slabs

Significant snowfall and recent strong winds have formed winds slab in the alpine and exposed treeline.

If triggered the wind slabs may step down to deeper layers resulting in large avalanches.Use caution in lee areas. Recent wind loading have created wind slabs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1.5 - 2.5

Persistent Slabs

These slabs will be most susceptible to triggering in shallow areas. This type of instability will linger for a while yet. The significant storms we've seen recently have overloaded these layers, priming slopes to fail only awaiting a trigger.

Avoid thin, rocky or unsupported slopes.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible - Likely

Expected Size: 2.5 - 3.5

Cornices

Cornices have become reactive in the last week. Strong winds, fluctuating temperatures and significant snowfall has contributed to these loitering hazards failing.

Pay attention to overhead hazards like cornices which could easily trigger the deep persistent slab.

Aspects: All aspects.

Elevations: Alpine.

Likelihood: Possible

Expected Size: 2 - 3