Avalanche forecast

West Slopes North

Northwest Avalanche Center
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Avalanche danger

Sun
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
1 · Low
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Highlights

Upper-elevation slopes holding wind drifted snow are where you are most likely to trigger a slab avalanche. Use lower angle, supported terrain to navigate around steep, wind loaded start zones. You may find avalanche danger a touch higher farther west in the forecast zone where there was heavier snowfall and stronger winds.

Avalanche problems

  • Wind Slabs

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

    Anywhere from 6 -12” of new snow fell in West North, often accompanied by moderate to strong winds. Snowfall had tapered by Friday afternoon but moderate winds will continue to transport snow in exposed terrain throughout the night. Wind slabs initially formed on a variety of surfaces including slick crust, old settled snow, or a thin layer of faceted snow or surface hoar overlying crust. At lower elevations, the bond to the underlying crust was reported to improve by the end of the day, but it could be another story as you gain elevation.

    Keep an eye out for the typical signs of wind transport like scoured ridgelines, fresh drifts and cornices, and slabby, dense-looking snow to figure out where wind slabs lurk. Monitor changes in new snow depth and stiffness as you climb higher and change aspects. Evaluate the uppermost layers with hand pits, test slopes, and other informal tests. Some steep slopes at mid and upper elevations will likely produce avalanches while others won't. It’s up to you to figure it out. Or just stick to lower-angle slopes for another day and let fresh slabs bond before taking on bigger terrain.

    Example of smooth wind slab on the left and scoured snow on the right.

Avalanche Discussion

Anticipate small loose snow avalanches in areas where unconsolidated new snow has a poor bond to the slick crust below. You can definitely get some snow moving with you down the hill if descending steep terrain. If we see any sun on Saturday, steep cliffy areas will shed snow and start loose snow avalanches on slopes below. Keep an eye on what is above you, especially during periods of warming or sun.

Observers in the Baker Backcountry reported shallow slabs that were easily triggered on wind loaded slopes at mid and upper elevations. Signs of instability and avalanche danger generally increased when climbing into upper elevations where the wind had created more of a slab. Warming also made the snow more slabby and moist snow was found at the surface at and below 5000’.

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