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
1 · Debole
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In sintesi

Rainfall should taper off by Thursday morning, but wet, saturated snow will remain. Avoid travel below glide cracks, snowy cliffs, cornices, or other steep, snow-covered features that could shed wet snow. Anticipate landslides and downed trees when accessing trailheads off - or maybe even on - the beaten path. 

Problemi valanghivi

  • Glide Cracks

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1.5–2.5

    The anticipated cool-down in temperatures and the end of precipitation should quell avalanche activity where there is still enough snow to slide. But don't expect any snowpack left standing to dry up immediately. Depending on elevation and the extent of snow cover,  there is still a low chance of seeing glide, wet loose, and wet slab avalanches, cornice falls, or just blocks of snow shedding from rocks and cliffs.

    The main danger isn't so much triggering a wet avalanche on steep snow-covered slopes; it's that wet, saturated snowpacks tend to unload sporadically even after precipitation ends. Keep an eye on what is above you if you make it into the mountains on Friday, and don't linger under anything else that looks wet, sketchy, and poorly attached to the mountain.

     

    (12/9/2025)

    Recent glide avalanches in the Baker Backcountry. 

    Photo: Zack McGill

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–1.5

    A few inches, or maybe more, of new snow should accumulate at upper elevations if snow levels drop before the end of precipitation. The dense new snow should be right side up, but you could still find small pockets of recently wind loaded snow. 

    Not many will make the journey to upper elevations on Friday. If you do, look for signs of active wind loading and keep track of new snow depths and layering as you gain elevation and change aspects. Any new slabs should be small, but they can still take you for a nasty ride down slopes with lots of exposed rocks or other ugly terrain features.

    (3/3/2021) 

    Looks for pockets of shallow but fresh wind slab where you see active wind drifiting.

Avalanche Discussion

The full length of the Cascade Range has just received an obnoxious amount of rain, and there's still another 2 inches of precipitation in the forecast overnight into Thursday morning.  Weather stations in West North are showing anywhere from 3.5 to 5.5 inches of precipitation in the last 24 hours, most of which fell as rain. A few Snotels in the eastern part of the forecast zone did show a net gain in snow depth. But with ridgeline temperatures climbing into the high 30s and low 40s through the day, it's safe to say it is still raining and melting away snow in most areas.

What has been the outcome so far besides river flooding and landslides? It's hard to say. If this sort of rain fell on a healthy, mid-winter snowpack, we would expect to see very large to historic-sized avalanches run full length to the valley bottom, laying waste to anything in their path.  But at mid-elevations, the snowpack was dismal, and much of what is out there had already seen plenty rain, warming and avalanche activity.  Snowpack depths quickly increased as one climbed above 6000 feet, so drier snow up higher likely had a more adverse reaction to rainfall as usual.

Between heavy rain and poor visibility, no backcountry avalanche observations were submitted as of Wednesday afternoon. But it's a safe bet that upper elevation areas experienced some amount of natural activity in the form of wet loose and other types of wet avalanches. Continued rainfall is also likely to have produced more glide avalanches, like those reported earlier in the week.

With the warm start to the 25-26 winter season, we have less snowpack information than usual to start daily forecast operations. For zones and elevation bands with less snow than needed for avalanche hazard, we will issue a forecast with No Rating. Anticipated avalanche and weather conditions will still be updated daily. NWAC will issue an avalanche danger rating for a zone when enough snow to produce avalanches has accumulated at middle and upper elevations.

 

 

 

 

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