Bollettino valanghe

East Slopes Central

Northwest Avalanche Center
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Pericolo valanghe

Sat
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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Non aggiornato — questo bollettino è scaduto 6 months ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Particularly where the snowpack appears wind affected, it is possible to trigger a large and surprising avalanche that breaks 1-2 feet deep. If enough rain falls along the Cascade Crest, the likelihood of triggering big and small avalanches in these areas will increase. You can reduce your risk by choosing more sheltered terrain or smaller, simpler slopes.

Problemi valanghivi

  • Persistent Slabs

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

    Wind, warmth, and light accumulations of new snow maintain the likelihood of this problem despite some signs that poor snowpack structure is healing. You can generally find these buried weak layers 1-1.5 feet down. The most likely place you'd trigger a slide is in exposed wind-loaded terrain, and weak layers can be buried even deeper here, too. New small wind slabs could be forming throughout the day in these areas as well, but only immediately adjacent to the Cascade Crest. By the afternoon, some rain along the Crest could reach middle elevation terrain. If water works its way down to buried weak layers, this could reinvigorate instability by the end of the day.

    We have limited data for the zone, which creates sizeable uncertainty around an already tricky problem to manage in the backcountry. If you plan to travel near a neighboring forecast zone, consider reading that forecast as well to equip your toolbelt with more information. Either way, ease into terrain slowly. You may or may not get clear feedback from the snowpack before triggering a large slide in consequential terrain. 

    (3/1/2026)

    Snow machine triggered large (D2) persistent slab and self extricated on 2/28. Darland Mt. NE aspect, 6700 ft.

    HS- AMu-R2-D2-O @ NE, 6700' Photo: Northwest Avalanche Center

  • Loose Wet

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

    Freezing levels are expected to start around 3500 ft and reach 6000 ft by the end of the day on Friday. That means precipitation falling near the Cascade Crest will fall as rain below these elevations. Most avalanches should be small, but if it rains enough for water to trickle down to buried weak layers, you could be in for a large and surprising slab avalanche. Additionally, a small wet loose avalanche could trigger a bigger persistent slab avalanche.

    If you're punching deeply through wet, heavy snow, steer around very steep terrain where you could be knocked off your feet and carried into terrain traps below. If curiosity strikes, you can dig in and see how far down the snow is getting wet within the snowpack. If you can easily make a snowball with a gloved hand or even squeeze water out, that snow is not dry. Fresh rollerballs, pinwheels, and large chunks of snow falling from terrain features indicate rising instability.

Avalanche Discussion

The very western edge of East Central continues to pick up incremental snowfall, while the rest of the zone has seen considerably more sunshine over the week. Friday will be similar; however, the whole zone should remain under full - mostly cloudy coverage. That won't stop freezing levels and temperatures from rising throughout the day, and continuing to hike up going into the weekend. In the short term, this warmth and rain will increase instability, both with wet snow problems and the persistent slab problem. In the long term, we may benefit from wetted snow refreezing and creating new supportable crusts or wiping out faceted snow. 

The weak layers we are tracking are the 2/13 buried surface hoar and facets around the 2/7 crust. These two layers are very close together and can often appear as a single, weak layer. Their depth and prominence vary across the zone, especially on sun-exposed slopes and at lower elevations. Despite limited data points, we have moderate confidence that this weak snowpack structure exists across most of the zone and have growing confidence that these layers are healing. An NWAC Forecaster was in the backcountry around Mission Ridge on Thursday and got no notable snowpack test results. They also reported a semi ski-supportable crust on a NW aspect, indicating that even more polar aspects are starting to feel the effects of warm weather. This is one data point for a big zone, however. Neighboring zones continue to report more recent activity, especially East North. You'd be jumping the gun if you decided to step all the way out into big, consequential terrain on Friday.

Prepare for a steep entry fee to get to higher elevation terrain where enough snow exists for on-snow recreation. Blewett Pass remains largely unskiable. Even the groomed roads in the Salmon La Sac, where more snow has fallen, are very patchy. Give yourself extra time and precaution to tackle these conditions.

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