Bollettino valanghe

West Slopes North

Northwest Avalanche Center
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Pericolo valanghe

Fri
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
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In sintesi

If you find wet punchy snow, you're in the lower to mid-elevation range where wet loose avalanches are possible or snow may shed from steep rock faces without warning.  As you ascend and encounter drier snow, you may trigger slab avalanches in recent snow on steep open slopes.  

Problemi valanghivi

  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2

    The snow-line has oscillated between lower and mid-elevations over the last few stormy days.  As you poke above this transitionary zone you're more likely to find dry snow , a lack of crusts in the upper snowpack and deeper drifts on lee aspects.  Step into these areas with a healthy amount of caution, we know very little about the stability of recent storm layers at upper elevations.  Clues like long-shooting cracks from your feet, whumphing, or evidence of recent avalanches are signs to avoid nearby similar slopes.  You can use small test slopes and handpits to get a sense of the upper snowpack. 

    Example photo: Human-triggered slab avalanches are possible in areas where you find dry snow.  

    Photo: Irene Henninger

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2

    Another day of snow levels and precipitation around 3500-4500' means another day with a moving target for wet loose avalanches. If you find wet and sticky snow, you may trigger wet loose avalanches on nearby steep slopes.  Most wet loose avalanches are likely to be small, but they could be larger depending on the slope, if there's a crust to run on and how much snow is available for entrainment.  Be mindful of triggering even a small wet loose avalanche near terrain traps.  

    Temperatures have hovered near or above freezing at lower elevations for days.  These places are less likely to see new wet loose avalanches but could see big blocks of snow shed from steep faces.  Move along and don't spend time below these features or anywhere you see glide cracks opening.  These avalanches are unpredictable and it's better to just put space between you and the potential hazard. 

    Avoid terrain where even a small avalanche would be dangerous.

    (1/19/2024) A small wet loose avalanche at low elevations on the east side of Herman.

    Photo: Jason Speer

Avalanche Discussion

NWAC forecasters and ski area professionals found a snow-line bumping around 3500-4500' in different areas of the West North zone Wednesday.  Small wet loose avalanches could be easily triggered in some areas, with signs of older small natural wet loose avalanches easy to find at lower elevations.  Tuesday was more active with up to size 2 (large) wet loose avalanches reported in the Baker backcountry. 

The Mt Baker Ski Area triggered a very large slab avalanche with explosives on Hemispheres, with a crown 4-5 feet deep on Tuesday. We don't have specifics on whether it was wet or dry at the failure plane or what layer it failed on. The avalanche may have failed in a weak layer above the 12/30 crust.  Deeper instabilities in the snowpack will become more of a concern as we head into a wet and increasingly mild weekend.  Information is limited, espcially from upper elevations.  If you make it out - please let us know what you see by submitting an observation. 

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