Bollettino valanghe

West Slopes South

Northwest Avalanche Center
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Pericolo valanghe

Mon
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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Non aggiornato — questo bollettino è scaduto 2 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

It may be quiet to start the day, but another storm is on its way. Look for the avalanche danger to rise as increasing winds build fresh slabs higher in the terrain. Don’t trust pockets of wind-drifted snow on steep, high consequence slopes. 

Problemi valanghivi

  • Wind Slabs

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

    In the morning, you may find a few small wind drifted pockets that formed Saturday night. As winds increase and snow returns during the day, look for wind slabs to become more common and grow in size. This will be particularly true on the volcanoes where you might encounter a slab 1-2 ft thick. 

    You won’t have to look hard to figure out which slopes are being loaded. Blowing snow and sharp drifts will point toward these growing slabs. Be leery of actively wind-loading slopes, especially above cliffs and rocks where even a small slide could turn into a terrible ride. 

    On exposed slopes, winds will likely quickly scour the snow down to a firm crust. While you don’t have a wind slab issue here, it could be very icy instead.

    (12/8/2024)

    Example: Actively blowing snow on top of Bullion Peak. A bullseye visual clue that wind loading is occurring on leeward slopes.

    Photo: Andy Harrington

Avalanche Discussion

Things look pretty quiet to start the day and you might not find much in the way of avalanche hazards. As our next storm arrives, that will slowly change, but it will take some time. A newly forming surface crust (the Solstice Crust) will keep most of the snowpack “locked up” and avalanche concerns generally focussed on the few inches of new snow. As we move ahead, we expect this layer to be our “new ground” and we don’t have any layers of concern below this curst at this time. 

Close to the rain-snow-line, wet heavy snow might dribble down the hill and form very small wet loose slides. Or, you may push a tiny avalanche over the firmer crust. These mini slides shouldn't post too much risk. Down low, the snowpack should be well situated to deal with whatever rain the storm throws its way. The snow level might be much higher in the western portions of the zone near Mt St Helens than you find closer to the crest like Crystal and White Pass. 

If we have a question mark about current conditions, it’s the highest reaches of our forecast zone. Stormy weather has largely kept travelers out of terrain above 7000ft. It could be a bit drier up high, but we expect avalanche concerns to be largely the same. 

Overall snowpacks across the zone are impressive. Even still many creeks remain open and create the most common travel concern. Below 4000ft, the snowpack is much thinner and other early-season obstacles exist.

Regioni coperte