Bollettino valanghe

Stevens Pass

Northwest Avalanche Center
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Pericolo valanghe

Thu
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
2 · Moderato
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Non aggiornato — questo bollettino è scaduto 5 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Conditions may become dangerous on upper elevation slopes by mid-day with heavy snowfall and wind drifting. Be ready to step it back once about 6" of new snow has accumulated or if you see signs of instability such as shooting cracks and recent avalanches. Avoid slopes steeper than 35 degrees near and above treeline later in the day or during times of heavy snowfall.

Problemi valanghivi

  • Storm Slabs

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

    Snowfall will begin in the early morning, and around 8" or more could accumulate by the end of the day. Avalanche danger will rise each hour of the day and may reach Considerable by the afternoon with heavier snowfall. The likelihood and potential size of storm and wind slabs will increase by afternoon, and wind drifting can be expected on upper elevation terrain. Below treeline you may trigger small storm slabs on very steep or unsupported slopes. Be ready to step back and avoid consequential terrain during times of heavy snowfall.

    You can do quick hand shears, switchback ski tests, and use small test slopes to identify how well new snow is bonding. Shooting cracks and fresh, slab avalanches are direct signs of instability. Search for signs of wind loading such as pillows and textured surfaces. Loose avalanches and sluffs may also run easily on steep slopes. Avoid slopes steeper than 35 degrees with over 8" of new snow, and during times of heavy snowfall or wind loading.

    An example of a skier triggered slab on Tye Peak which occurred earlier this year, similar to what you might see.

Avalanche Discussion

Another storm will arrive early Wednesday morning, bringing the potential for heavier snow with a Puget Sound Convergence Zone in the middle of the day for Stevens Pass. Slightly warming temperatures may make for a somewhat upside-down storm slab as the daytime warms up. Winds will be strong enough to drift the falling snow into thicker slabs near ridgetops.

Give cornices plenty of room when traveling on ridges and stay out from under them. Cornices may build throughout the day Wednesday, and could be touchy to triggering. Several large glide cracks and a few glide avalanches were observed recently as well. If you notice crevasse-like cracks in the snowpack, avoid areas below the cracks. 

Deep persistent slab avalanches were a concern into early March, although at this point they appear dormant and unlikely. A layer of facets on a crust from Mid-January was responsible for these, and is now buried 8-9 feet deep. The last known deep slab avalanche in this zone was on March 1, and one was suspected in the West South zone on March 3. Major warming events later in spring and summer could trigger further rounds of avalanches on this layer. 

During the ongoing Covid-19 pandemic, continue to follow the latest guidance from local, state, and federal health officials. Avoid unnecessary risks that could impact first responders and stress medical resources.  Wear a mask when appropriate, practice social distancing, and consider recreating closer to home.

Regioni coperte