Avalanche Forecast
Regions:
New snow and wind will form new softer wind slabs that will be easy to trigger where they are sitting on old hard surfaces or crusts.
Deeper instabilities in the snow could still be triggered from thin and rocky snowpack areas.
Confidence
Moderate
Avalanche Summary
Old large avalanches can still be seen in many areas of the Haines pass, but no new avalanches have been reported since the weekend.
On Sunday, a suspected skier triggered avalanche was reported. This was a size 1 storm slab avalanche that likely occurred on Saturday.
If you head out in the backcountry, let us know what you are seeing by submitting a report to the Mountain Information Network.
Snowpack Summary
5-15 cm of new snow is now sitting on snow from last week's storm that delivered 50 cm of new snow to both passes. It has been heavily wind affected in the alpine, below 1300m the new snow is resting on a crust. In sheltered northerly aspects there is up to 30 cm of soft snow still hiding from the wind.
A buried weak layer of surface hoar can be found about 80-140 cm deep in Haines Pass. This layer is most prominent on northerly slopes sheltered from the wind. On other aspects, this layer is a hard melt-freeze crust with weak facets around it. This layer has been most problematic in alpine terrain. The remainder of the middle of the snowpack is consolidated and strong.
Weak faceted grains are found near the base of the snowpack, particularly in thin snowpack areas and a thick melt freeze crust is directly on the ground in many inland areas.
Weather Summary
Wednesday Night
Cloudy with snowfall, 5 to 10 cm of accumulation. Strong easing to moderate south through to southeast sustained ridgetop winds. Alpine temperature low -8°C. Freezing levels valley bottom.
Thursday
Cloudy with snowfall, 5 to 10 cm of accumulation. Light south ridgetop winds. Alpine temperature high -5°C. Freezing levels rising to 600 m by mid day.
Friday
Cloudy with afternoon clearing, isolated very light flurries, trace to 1 cm of accumulation. Light south ridgetop winds. Alpine temperature high -5°C. Freezing levels rising to 600 m by mid day.
Saturday
Cloudy with afternoon clearing, isolated very light flurries, trace to 1 cm of accumulation. Light south ridgetop winds. Alpine temperature high -6°C. Freezing levels rising to 400 m by mid day.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Be carefull around freshly wind loaded features.
- Make observations and assess conditions continually as you travel.
- Watch for areas of hard wind slab on alpine features.
- In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
Avalanche Problems
Wind Slabs
New soft wind slabs are forming in areas nearest the coast and old hard wind slabs may still linger on north and west facing terrain features throughout the region.
Observe the wind loading pattern in the area as you move through the terrain, southwest winds will continue to redistribute available snow into fresh wind slabs in lees through the day.
Aspects: North, North East, East, South West, West, North West.
Elevations: Alpine.
Likelihood: Possible
Expected Size: 1 - 2.5
Persistent Slabs
A weak layer of surface hoar and/or faceted grains around a hard crust sit in the mid snowpack. This layer is buried around 80 cm in the eastern portions of the region and up to 200 cm around White Pass and Haines Pass.
This layer has previously produced widely propagating avalanches in alpine terrain and it is capable of being remotely triggered from a distance. The most likely area for riders to trigger it is in wind-sheltered, north-facing terrain, and in rocky terrain where the snowpack is thin.
Aspects: All aspects.
Elevations: Alpine.
Likelihood: Unlikely - Possible
Expected Size: 2 - 3