Bollettino valanghe

East Slopes South

Northwest Avalanche Center
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Pericolo valanghe

Sat
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 avalanches are signs that new and old wind loaded slopes are abundant. Wet snow avalanches are likely in areas where you encounter heavy, wet snow. Stick to low angle, wind sheltered terrain if you find signs of instability.

Problemi valanghivi

  • Wind Slabs

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

    Another storm system rolls through starting on Thursday night accompanied by moderate wind. This will build fresh wind slabs on lee slopes at middle and upper elevations. After Thursday's powerful storm, you could still find older slabs at all elevations. They will be loitering in atypical locations i.e. lower down on slopes and in exposed terrain at lower elevations. Fresh slab formation can overload older wind slabs and produce a bigger and even more consequential avalanche. Warm temperatures and rain likely healed most wind slab instability found below 3500 feet.

    Be on the lookout for blowing snow which will tell you where slopes are being freshly loaded. Rippled, uneven snow surfaces indicate wind transport, but this may not be obvious if obscured by new snow. If you encounter hard snow surfaces, presume that deeper slabs can be found just below ridgelines and in cross-loaded gullies. Cracks shooting from your skis or sled indicate that you have found an unstable slab. 

    (12/26/2024)

    Mission Ridge Pro Patrol triggered  wind slabs with ski cuts on12/26.

    Photo: Payton Schiff

  • Loose Wet

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

    Rain mixed with snow will impact lower elevations Thursday night into Friday. This 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. If you start to get 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.

    (12/23/2024)

    A natural loose wet avalanche (D1) occurred above Valhalla Lake mid-day. 5,400ft, W in the Stevens Pass zone.

    Photo: Josh Hirshberg

Avalanche Discussion

The Christmas/Boxing Day storm delivered! Telemetry shows that an average of 1-1.5 feet of new snow fell throughout the zone. What is more notable, however, is the wind that co-occurred. Just over the border in the West South zone, White Pass and Crystal Mountain ski areas contended with gusts up to 90 mph. An NWAC Forecaster experienced gale force winds and trees falling over in the southern end of the East Central zone. It's safe to assume that in the East South zone too, it was not a day to contend with Mother Nature.

The zone could see another inch of water falling predominantly as snow near the Cascade Crest through Friday afternoon. If you find cracking and collapsing in more sheltered areas, you have found storm slab instability. Step back from steep slopes if you encounter these signs.

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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