Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
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Avalanche danger

Wed
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Highlights

On Tuesday, you can still trigger an avalanche on wind-loaded slopes where recent snow may be drifted into thicker and stiffer slabs. Remember that softer wind slabs can be challenging to identify. Ease into the terrain and carefully assess snow stability before committing to steeper slopes.

Avalanche problems

  • Wind Slabs

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

    The Pass received up to 18" of snow late Sunday thru Monday afternoon. With the modest wind speeds, we are most concerned about the potential for wind slab avalanches on slopes with a good bit of exposure near ridge lines, cornices, chute entrances, cliff bands, and convex rollovers. Slab size will grow as you increase in elevation. Your eyeballs are typically one of the best tools for identifying wind slabs, but these soft and subtle slabs could be hard to detect on Tuesday, making the problem challenging to manage. Though we don’t expect large avalanches, even small slides can have serious consequences in steep or technical terrain. Use hand pits, uptrack tests, and safe test slopes to gauge slab reactivity. Since wind slabs generally need a few days to heal, the best bet on Tuesday is to avoid wind-loaded slopes and take advantage of the much-improved riding conditions out of the wind zone.

    (12/12/2024)

    A small crown from skiers intentionally triggering wind-drifted snow on a steep slope.  These types of avalanches remain possible on Tuesday.

    Photo: Andy Harrington

Avalanche Discussion

The Pass won the Convergence Zone Sweepstakes on Monday, where backcountry travelers found up to 18” of fresh snow at the mid and upper elevations. Summit at Snoqualmie Pro Patrol noted signs of a small natural avalanche cycle on leeward slopes at the highest elevations as well as generally good skiing with few signs of instability lower down on the mountain. A backcountry party near the Snow Lake Divide found good ski conditions, stability, and noted no signs of wind transport where they travelled, though visibility was limited all day.

This recent snowfall came in largely right side up along with cool temperature and light wind. Still, as indicated by the Patrol’s observation of a natural cycle, even modest winds can form slabs in favored locations, and these should still be on the radar on Tuesday. We expect any activity to involve the recent snow and to run on the 12/28 interface, now buried between 1-2 feet below the surface, depending on your elevation and exposure. With minimal new inputs into the snowpack and just a quick AM appearance by the sun, we are hopeful that stability will continue to improve through the day on Tuesday. That said, if the sun comes on for longer and stronger than anticipated, give a wider birth to steep slopes as sun on fresh snow can lead to increased reactivity.  

Finally, with clearing skies and cool temperatures, snow surfaces may begin to weaken. The next system comes in with relatively low windspeeds and just a bit of precipitation; a good combination for capping and preserving a layer of surface hoar or near-surface facets. If you get out, please let us know what you find within and on top of the snow!

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