Bollettino valanghe

East Slopes North

Northwest Avalanche Center
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Pericolo valanghe

Sun
Alta quota
2 · Moderato
Limite del bosco
1 · Debole
Sotto il limite
1 · Debole
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In sintesi

You can trigger small loose avalanches on steep sunny slopes. Cornices hang off of many ridges and could fall with warming temperatures. Give cornices plenty of space and stay well out from under where they could fall. 

Problemi valanghivi

  • Cornices

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

    Warming temperatures and sun will again raise concern for cornice fall. Cornices are large and still loom on many upper elevation ridges near the Highway 20 corridor. If you're traveling on ridges, make sure to stay well away from the edge. Travelers are often surprised when cornices break further back than they expect. Choose terrain that minimizes exposure to overhead cornices. Make sure to stop and regroup in places where cornices can't reach you from above.

    Earlier in the week, winds formed drifts at upper elevations. While wind slab avalanches are now unlikely, a cornice fall could be big enough to trigger them. If you see glide cracks, stay well out from underneath them. Glide avalanches are notoriously difficult to predict and can be destructive when they release. 

    (3/24/2021) Overhung cornices in Cutthroat Creek, 6,400ft, ENE. Photo: Josh Hirshberg

  • Loose Wet

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

    Warming temperatures and sunshine could trigger loose wet avalanches on steep, sun-exposed slopes. Look for signs of instability such as rollerballs and fan-shaped avalanches as the temperature warms. The potential size of loose wet slides will increase at higher elevations and near to and west of Washington Pass. Don't let these predictable avalanches catch you by surprise in or around terrain traps or extreme terrain.

    Loose dry avalanches are possible on very steep, shaded slopes above 6,000ft. Ride cautiously in steeper terrain knowing that you could initiate sluffs that may entrain loose snow and grow larger.

    (3/24/2021) A number of small natural loose avalanches and overhung cornices in the Cutthroat drainage. ENE, 7,300ft. Photo: Josh Hirshberg

Avalanche Discussion

On Wednesday in the Cutthroat drainage, observers reported around 5" of new snow with 1 foot since the 21st. Shallow wind drifts were observed near ridgetops, and small loose dry avalanches were easily triggered on slopes steeper than 40 degrees. The new snow fell on a recently buried sun crust on all aspects but direct north. On northerly and shaded aspects, observers were still reporting cold dry snow above about 6000' in elevation. An observer also reported a large recent glide avalanche in Cutthroat at around 5,400ft that appeared to have occurred since March 21st.

Since the beginning of March, the region has undergone a slow warming trend and now steady but cool temperatures. Observers have reported sporadic cornice fall.  The mid-January weak layer that plagued most of the Cascades for the month of February has not been a major concern near Washington Pass.

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