Bollettino valanghe

East Slopes North

Northwest Avalanche Center
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Pericolo valanghe

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

In sintesi

Avoid steep wind-loaded terrain where you are likely to trigger an avalanche in wind-drifted snow. These might start small but could step down to deeper layers, becoming large. Recent snow fell on a weak and variable snowpack, and a lot of uncertainty exists. Travel conservatively, give yourself greater safety margins, and stick to low-angle terrain. 

Problemi valanghivi

  • Wind Slabs

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

    Strong winds drifted the fresh, low-density snow into wind slabs over weak or slick snow surfaces. While there isn't a huge amount of fresh snow, small wind slabs could be sensitive, step down to deeper weak layers, and break wider than anticipated.  Avoid steep slopes below ridgelines, the base of cliffs, and cross-loaded terrain features. Textured surfaces and visible blowing snow are great visual clues to identify wind-affected terrain. With the variability in the old snow surfaces, this problem could be tricky to pin down, and similar slopes may not react the same. With high levels of uncertainty, the best management practice is greater safety margins between you and steep open slopes. 

  • Storm Slabs

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

    The most dangerous areas will be shaded northern aspects. Widespread weak facets on the old snow surface could make avalanches easy to trigger. These slides could break widely across terrain features or might even be triggered from below. With an uneven distribution of old surfaces, quick handpit tests, kick turn tests, and test slopes you would typically use to assess stability might not be reliable. Adjacent slopes could have significantly different stability. Consider the high level of uncertainty, give yourself greater safety margins, and enjoy the return to winter on low-angle sheltered terrain with limited overhead exposure. 

    Fast running dry loose avalanches are also likely, so manage your terrain appropriately by stopping in safe locations, and don't sluff out your backcountry partners below. 

    (2/1/2025) This small sled triggered storm slab is a great example of how sensitive some slopes may be on Sunday. 

    Photo: Will Govus

Avalanche Discussion

In the last 48 hours, 8-10 inches of snow accumulated in the Washington Pass area. Reports of small natural and triggered wind slabs, storm slabs, and dry loose avalanches from Friday and Saturday are widespread. While most of these avalanches were small, one reported avalanche stepped down to a more deeply buried weak layer. This certainly wasn't a significant storm by Cascade standards, making the reactive nature of the recent snow and deeper instabilities particularly concerning. It highlights just how weak the old snow surfaces were and could point to lingering avalanche concerns moving forward. 

Your best course of action is to keep your decision-making simple and choose conservative, simple terrain. If you choose to venture into avalanche terrain, consider the unpredictable distribution of old snow surfaces.  Snow fell on slick crusts on steep southerly terrain and weak faceted snow on northern aspects. Meanwhile, east and west aspects likely harbor a mix of both surfaces. As we gain more information, we'll likely be able to narrow the areas where we suspect avalanches are most likely. However, gaining confidence in the distribution takes patience, time, and many observations.

You can help us gather more data by submitting an observation HERE or via the Avy App. 

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