Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
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Avalanche danger

Thu
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

Increasing clouds and winds along with cooling temperatures will gradually lower the chances of wet snow avalanches during the day on Wednesday.  Use caution on steep slopes if you find yourself sinking into wet punchy snow deeper than your ankle.  In isolated areas, loose wet avalanches could still grow large and powerful. 

Avalanche problems

  • Loose Wet

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

    After a mild Tuesday night,  increasing clouds and winds along with falling snow levels on Wednesday afternoon will decrease your chances of triggering a loose wet avalanche.  While you're less likely to trigger a loose wet avalanche on Wednesday, if you get a slide started, it could still become large and powerful in terrain where it can gouge down to weak wet snow near the surface.  This isn't an avalanche problem you want to mess around with; steer around any steep slope where you sink into wet punchy snow deeper than your ankle and move to simpler terrain. 

    Rain at lower elevations in the afternoon probably won't greatly increase the likelihood of loose wet avalanches, but it's another factor to consider even as upper elevations begin to firm up.  There are many terrain traps at lower elevations like open creeks, trees, rocks, etc that you don't want a deceptively powerful wet snow avalanche to knock you into. 

    You may find debris from recent loose wet avalanches as you travel on Wednesday.  

    Example photo from (3/2/2022) 

Avalanche Discussion

It was a warm day at the Pass with mountain temperatures pushing well into the 40s, and even 50s at Pass level.  A mix of low clouds and March sun helped keep the snow surfaces wet during the day.  The snowpack settled rapidly with the warm temperatures; the total snow depth measurements at both Alpental base (3100') and the mid-station (4350') decreased an impressive ~8" over 24 hrs ending at 5 pm Tue.  On Tuesday, we received one public observation of a shallow wet slab avalanche below 4000' on McClellan Butte.  Did you see evidence of wet snow avalanches? Let us know by submitting an observation.  

The Snoqualmie Pass area received about 8-14" of snow Sunday night through mid-day Monday,  with the higher totals recorded above 5000'.   A slow warming trend occurred throughout the storm and produced a natural avalanche cycle.   Avalanche professionals noted a loose wet avalanche cycle below 4000' as temperatures warmed Monday.  Backcountry travelers observed D1-D2 natural storm slabs and very touchy skier-triggered storm slabs 8-10" deep during the day.  

While we're mostly concerned about avalanches involving the most recent snow, it's worth keeping in mind that we're still in a period where conditions may be affecting deeper weaker interfaces in the snowpack.  A layer of weak facets sits over a very thick and stout crust on NW-NE aspects near and above treeline. This layer is likely 3 ft or more deep in the Snoqualmie Pass zone.  So far, only one small avalanche (3/18) has been reported on this layer in the zone.  That said, until we strengthen and lock up the snowpack, it would be wise to factor in the possibility of a very large avalanche releasing down to this interface with the right trigger (ex: cornice fall) in the right spot.  

Regions covered