Avalanche forecast

West Slopes North

Northwest Avalanche Center
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Avalanche danger

Tue
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

Natural and human triggered avalanches in steep, wind loaded terrain were reported Sunday afternoon. Similar avalanches will be slightly more difficult to trigger Monday but still pose a significant hazard to backcountry travel. The safest plan is to just avoid steep slopes you suspect hold wind drifted snow 

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2

    There is a good chance that wind slabs from the latest storm will be hidden by at least a few inches of snow that fell with no wind. In some places wind slabs formed over the old snow surface of weak facets and/or surface hoar that could make slabs easier to trigger and also delay stabilization.

    • Look for signs of wind affected snow like scoured ridgelines, fresh cornices, and smooth drifts to figure out the wind loading pattern in the surrounding terrain. Shooting cracks mean you found reactive wind slab.
    • Keep track of differences in how much light snow you are moving through vs. how stiff the snow feels underfoot. Deeper snow and softer layers below likely equal less wind loading while stiffer snow underfoot is probably wind slab.
    • Take a few minutes to look for and assess facets or surface hoar that could be at the old/new snow interface. 
    •  Test slopes and other assessment tools can help you evaluate the bond of wind slabs to the layers below.

     

    (2/26/2023)

    A small, remotely triggered wind slab on the south side of Herman @ 4700', triggered from where the two skiers are standing. There was a noticeable collapse when it released and facets were found in the bed surface.

    Photo: Jason Speer - Baker Mountain Guides

  • Loose Dry

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    There is no shortage of light, fresh snow out there. Many small, human triggered avalanches - somewhere between dry loose and very, very soft storm slabs - were reported from steep, wind sheltered areas. They are probably not big enough to bury you but the outcome could be different with terrain traps in the runout or on big steep slopes where they can run far and entrain more snow.

    These kinds of avalanches shouldn’t take you by surprise - move slowly over steep rolls in wind sheltered terrain and stay alert to the amount of snow moving with you when descending.

    (2/26/2023)

    Human triggered dry loose avalanche in Swfit Creek just outside of the ski area boundary.

    Photo: Zack McGill - Cascade Mountain Ascents

Avalanche Discussion

Monday should bring continued cool temperatures, cloudy skies, and a few more inches of new snow by day’s end. The likelihood of seeing wet avalanche activity in the morning is quite low, but it won’t take much warming for all that new snow to react. Pay attention to sunny slopes overhead even if it feels too cold for anything to happen.

A few hours of visibility revealed a handful of natural avalanches to D2 around the Baker Backcountry. It also got some folks out onto steep, wind loaded slopes where they triggered slab avalanches up to D2 in size. No one was reported as caught or injured. Reported avalanches were on north through east facing slopes near treeline. Most occurred just below ridgeline but some were found mid-slope in cross-loaded features. Outside of wind affected terrain, the new snow lacked significant cohesion and released as very soft slabs or sluffed easily.

The latest storm put down up to 18” of cold light snow with steady, strong winds through Sunday morning. This resulted in a highly variable pattern of accumulation with 0”-24” on the ground depending on the aspect in relation to wind. 

Observers in Glacier Creek and the Sisters Range found less snow and no signs of natural avalanche activity. Wind effect in the Sisters was found down to low elevations while little was noted in Glacier Creek, probably due to being more sheltered from southerly winds.

Regions covered