Bollettino valanghe

East Slopes South

Northwest Avalanche Center
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Pericolo valanghe

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

In sintesi

Blowing snow, shooting cracks, and recent slab avalanches are signs that wind transported snow is unstable. Wet snow avalanches are likely in areas where you encounter heavy, wet snow. Stick to slopes less than 35 degrees where you find signs of instability.

Problemi valanghivi

  • Wind Slabs

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

    Yet another storm rolls through starting on Friday night accompanied by sustained moderate wind throughout the day on Saturday. Expect to find higher snow accumulations near the Cascade Crest. This will build fresh wind slabs on lee slopes at middle and upper elevations. Blowing snow will direct you to where slopes are being freshly loaded. Deeper, older slabs could still be found just below ridgelines and in cross-loaded gullies. Fresh slab formation can overload lingering older slabs, producing a bigger and even more consequential avalanche.  Look for wind loaded snow where you encounter hard, uneven snow surfaces and cornices.

    (12/27/2024)

    A small skier triggered wind slab avalanche in the East Central zone. The crown depth is 18 inches (12/27/24).

  • Loose Wet

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

    Fluctuating freezing levels mean warm temperatures and rain at middle and lower elevations. Rain on new snow will rapidly destabilize the upper portions of the snowpack. The typical progression of wet loose avalanches involves rollerballs and pinwheels that lead to point releases. Anticipate unstable wet snow if the snow is heavy and sticky. If you are getting rained on, you won’t want to be hanging out on or below large paths. Don’t linger in terrain traps where avalanche debris can concentrate and be aware of steep terrain overhead where avalanches can start.

    (12/26/2024)

    A small loose wet avalanche triggered with a ski cut. Tumwater Mtn, 2,000ft, ESE

    Photo: Josh Hirshberg

Avalanche Discussion

There is a lot of uncertainty about how well glued together things are right now. We lack data on snowpack conditions in this zone. Observations from the nearby East Central zone show a mixed bag of stability and instability. Additionally, weather models show variability in where the freezing levels will be on Saturday; they may creep higher than forecasted. What we do know is all of the ingredients are there for the aforementioned avalanche problems; new snow and wind higher up, warm temperatures and rain lower down. So in times like this, I don't plan to be the one waiting at the bottom of an avalanche path to find out how stable it is. Great dry snow riding and skiing can be found lower angle, sheltered slopes!

If you've ever found yourself wondering which direction you should look for wind loading if you encounter rippled, uneven snow surfaces, the best way I have found to think about it is that the "pointed" ridges of the ripples "point" towards the prevailing wind direction. It is a similar concept to how riming on trees usually happens on the side of the tree facing the wind.

With continued bouts of rain at lower elevations, contending with low tide conditions remains an issue. Watch out for exposed hazards such as stumps, downed logs, and open creeks.

Help NWAC forecasters reduce uncertainty by submitting an observation!

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