Archived

Avalanche Forecast

Jan 22nd, 2016–Jan 23rd, 2016

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

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

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

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: Northwest Inland.

Pay close attention to new snow amounts and whether or not the surface snow is loose or cohesive. Tricky conditions are likely if a cohesive slab forms.

Confidence

Low - Due to the number of field observations

Weather Forecast

Saturday: Cloudy with a chance of flurries. The freezing level is at valley bottom and winds ease to light. Sunday: Mainly cloudy. The freezing level is at valley bottom and winds are moderate from the southeast. Monday: Cloudy with light snow. The freezing level could rise to 600-800 m and winds increase to strong from the S-SE.

Avalanche Summary

There are very few observations from the region. No new natural avalanches have been reported. One size 1 skier-triggered avalanche was reported on Thursday. This occurred on a relatively small, shallow slope below treeline.

Snowpack Summary

An additional 5-10 cm of snow with moderate or strong southeast winds may be enough to form fresh, reactive wind slabs in lee features. In some places this could also activate buried surface hoar in the upper snowpack, generally found between 30 and 60 cm deep. Stay tuned to signs of instability like recent avalanches, whumpfing, and shooting cracks. The mid pack that was reported to be well settled may have now facetted in the shallower areas, and the deeper basal layers are almost certainly facetted and weak. We have not heard of any full depth releases on weak basal layers yet.

Avalanche Problems

Wind Slabs

Watch for pockets of wind slab in exposed lee and cross-loaded terrain. These wind slabs may release easily under the weight of a skier or snowmobile, especially where they are sitting on a persistent weakness.

Be cautious as you transition into wind affected terrain. >Choose well supported terrain without convexities.>

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 3

Persistent Slabs

New snow has been slowly accumulating over a layer of facets and surface hoar and may now be primed for triggering in some areas.

Watch for whumpfing, hollow sounds, shooting cracks or recent avalanches.>Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible

Expected Size: 1 - 3