Bulletin d’avalanche

East Slopes North

Northwest Avalanche Center
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Danger d’avalanche

Thu
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
2 · Modéré
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Périmé — ce bulletin a expiré 6 months ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Snow and wind could reinvigorate dangerous avalanche conditions. The most suspect areas for deep avalanches that fail on old weak snow layers are where the wind blows snow into stiff drifts below ridgelines. Choose conservative terrain in sheltered areas and steer clear of steep slopes with textured drifts or areas where you observe blowing snow. 

Problèmes avalancheux

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1.5–2.5

    With new snow and wind, we could begin to see avalanche activity increase on buried weak layers. This isn't a powerful storm, so we have a fair amount of uncertainty if reactivity of the persistent slab will increase. That said, both small, fresh wind slabs and deeper persistent slabs are in the cards in wind-loaded terrain. Smaller wind slabs could easily step down to deeper layers and become large. Look for textured surfaces, actively blowing snow, or pillow-like drifts to identify wind-loaded slopes. Given the weak snowpack and uncertainty, take a step back and seek out sheltered lower-angle terrain for recreation. Make sure to keep significant terrain margins between you and any large, open, steep slopes above. 

    Many of the recent persistent slab avalanches occurred on southern aspects, and warming could have contributed to the increased avalanche activity. We expect the cooler temperatures help reduce activity on steep, sunny aspects, but light rain or wet snow could produce avalanches in more sheltered terrain. 

    (2/28/2026)

    A widely propagating natural avalanche below Cutthroat Peak. This avalanche is suspected to have failed on weak snow over the 2/7 crust. 7000ft, S-SW aspectN-R4-D2.5-O 

    Photo: NCH

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2

    Temperatures are cooling, but the lower elevations will likely see mostly rain. So wet loose avalanches on northern aspects with previously soft dry snow should also be on your radar. Recently formed surface crusts and widespread wind-stiffened snow will likely limit wet avalanche activity on southern and more exposed terrain. Rollerballs are the first sign of wet avalanches, and while most will be smaller point releases on steep slopes, there is a chance of them triggering a persistent slab. You can avoid wet avalanches by moving to low-angle slopes as surfaces become wet. 

    (1/14/2026)

    An example of loose wet avalanches, broken cornices from January. Hinkhouse Peak. S, 7,400ft

    Photo: Josh Hirshberg

Avalanche Discussion

The jury is out on whether this modest storm will make it easier to trigger avalanches. But it's been a very active few days, and a conservative mindset is the best way to manage this tricky, weak snowpack setup. Hopefully, after Wednesday's storm, we'll have more confidence in how the snowpack is adjusting. 

Since midweek, there's been a widespread cycle of natural and triggered avalanches in the East North zone. On the 28th, observers reported widespread natural avalanches, and an individual was partially buried in a large avalanche in wind-loaded terrain. We suspect that the weak, faceted snow over the 2/7 crust is the culprit in many of these occurrences. Many avalanches over the last week have been large to very large, and some have had wide crowns. Some avalanches were shallower, more typical of wind slabs at the base of cliffs. 

1-2 feet below the surface is a weak layer over a crust (February 7th). Immediately above the crust are weak faceted grains and, in some places, surface hoar. The January 28th crust is thicker and another 6-12" deeper.  On southerly aspects, there are more crusts and less dry, weak snow on the surface. West of Washington Pass, overall, the layers will be deeper, with thicker crusts and more snow between them. Further north and east, in places like Hart's Pass and the Chewuch and Twisp River drainages, the snowpack is shallower and weaker. We have little recent information in the eastern mountains and suspect a very weak snowpack.

Régions couvertes