Bollettino valanghe

West Slopes South

Northwest Avalanche Center
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Pericolo valanghe

Fri
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 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Human triggered avalanche danger may be present on Thanksgiving Day at upper elevations and on the volcanoes, who received the bulk of the precipitation from the recent storm. If you notice signs of wind transported snow, use caution on slopes 35 degrees and steeper, convexities, and unsupported slopes where you could trigger avalanches more easily. Keep in mind that it is still early season and there are many natural hazards found on or just below the snow surface.

Problemi valanghivi

  • Wind Slabs

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

    Don’t be surprised to find some lingering wind slabs on Thursday, especially if you choose to venture to upper elevations or are on one of the volcanoes. You will be more likely to find these slabs on leeward slopes, at the base of cliffs, or on the sides of gullies throughout the zone. These slabs may continue to be reactive to human triggers, so be sure to take the time to identify wind-loaded features where getting caught in a slide would be consequential. You can keep an eye out for freshly built cornices, textured snow surfaces, or pillow-like piles of snow to help to identify potential wind loaded areas. Take the time to dig some hand-pits and play on small test slopes to give an indication of how sensitive these wind slabs may be. If you find that the snow is poorly bonded or experience clues of unstable snow such as shooting cracks or whumpfing collapses as you travel, seek out lower angle terrain.

    (11/25/2020) Test slopes can give you a lot of good information about how new snow has set-up after or during a storm. This test slope shows that storm slabs were sensitive and propagating easily on Wednesday in the Snoqualmie Valley.

Avalanche Discussion

Observations were limited in the West South after the storm, especially on the volcanoes and at the higher elevations, where the bulk of the precipitation was focused. In the neighboring Snoqualmie Pass zone, storm slabs and wind slabs were very active on Wednesday on a mid-storm layer approximately 2 inches above the old snow interface. In areas such as Crystal, some dry loose activity was reported earlier in the day after receiving a few inches of new snow. If you are traveling in an area of the West South that received more than a few inches of snow during the previous storm, ease into terrain slowly and be sure to make your own hazard assessment. Take note of what happened at Snoqualmie Pass where they received more snow, and apply that to what you are seeing beneath your feet. If the sun happens to make an appearance for a prolonged period of time on Thursday, take note of how the snow surface may be changing and keep the possibility of wet avalanches in the back of your mind. If you see rollerballs or snow shedding from trees, make your way toward shaded or lower angle terrain.

 

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