Bollettino valanghe

West Slopes North

Northwest Avalanche Center
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Pericolo valanghe

Tue
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

Dangerous avalanche conditions exist, and triggering an avalanche is likely. Your main avalanche concerns are in the new snow that's fallen since Sunday, which could be around a foot or more, as the peak instability of larger, deeper avalanches is probably behind us. Avoid travel on steep slopes where new snow amounts are 6 inches or greater, especially in areas where snow drifts into thicker, heavier deposits, or in areas where you're sinking several inches into wet, heavy snow. 

Problemi valanghivi

  • Storm Slabs

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

    You're most likely to trigger an avalanche in the new snow layer that sits over the older wet layer. Snow falling on Sunday night and more on Monday could amount to between 6 inches to over a foot of new snow that could avalanche. Even the upper portion of the lower elevation band will get enough new snow for the problem to present a concern down low.

    An increase in temperature during the day could make new storm slabs more reactive to a human trigger as the day progresses. Wind speeds will also be strong at times, and you can expect massive amounts of snow redistribution. In areas with thicker drifts, triggering an avalanche will be more likely. Natural avalanches could also result. Nevertheless, expect instability on all aspects, wind-loaded or not.

    On Monday, avoid slopes greater than 35° and choose sheltered, lower-angle terrain. If you see any natural avalanche activity, avoid travel beneath large, steep slopes as well. 

    (1/4/2025)

    Example photo: A human-triggered avalanche that failed where the slope rolled over and became steeper. This is similar to what you can expect to see on Monday. 

  • Loose Wet

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

    The lower elevation snowpack may have a couple of inches of new snow over the old, wet layer. This newer snow is what you're most likely to trigger an avalanche or see natural activity in. As you travel higher, nearing the mid-elevation band, more snow sits over the old, previously saturated layer and may avalanche as temperatures increase during the day. 

    If you find moist or sticky new snow, search for natural activity like rollerballs or small, wet slides fanning out. As the day progresses and warms, more avalanches may result. Likewise, you may be able to trigger one of these avalanches on a steep slope. Beware of small amounts of snow entraining larger amounts as they slide downhill, which could result in a larger and more dangerous slide. Avoid travel on steep slopes where you see any natural activity and terrain beneath these steep slopes as well.

    (2/18/2025)

    Wet loose avalanche activity in the Baker backcountry, which may be similar to what you see on Monday. 

    Photo: Zack McGill - Cascade Mtn Ascents

Avalanche Discussion

A forecaster in the Baker backcountry on Sunday (observation) found evidence of old avalanches which likely occurred Saturday and overnight into Sunday, when peak precipitation and avalanche activity occurred. Many of the avalanches were large, D2-2.5, and a few were very large, D3-3.5 stepping down into deeper, old layers, running full path. Mid and upper elevations had a slight surface freeze over the wet, mushy snow, and the old snow layer appears to have adjusted to the wetting. Deeper avalanche concerns have likely subsided, although it's not completely out of the question that an odd one might still happen. They were surprised to find the rain had only thoroughly wetted the top foot, maybe two, of the snowpack. 

As of Sunday evening, the Heather Meadows telemetry received 4 inches of water since Friday. Nearly 2 inches arrived in a 12-hour block Saturday evening, when rain transitioned to snow at most elevation bands. Given the relatively short period of warming and for Baker standards, "smaller" amounts of rain, our usual suspected glide avalanche problems didn't appear. Over the next several days, we can expect to receive even more precipitation at more normal snow levels, and warming temperatures looking further into the week. 

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