Bollettino valanghe

West Slopes South

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

Another day of warm temperatures on the volcanoes Saturday could drive Wet Loose avalanches, while areas closer to the crest could contain a lingering Wind Slab. Take note of changing conditions throughout the day and avoid slopes steeper than 35 degrees if you encounter wet and weak snow surfaces. As you ascend in elevation, be aware of wind-drifted piles of snow where you could trigger an avalanche more easily.

Problemi valanghivi

  • Loose Wet

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

    If you find yourself in the mountains enjoying the sunshine on Saturday, keep your eyes open for new rollerballs or the snow surfaces becoming wet and sticky. If you see these signs, it means that solar input and high freezing levels may have teamed up to destabilize the snow surface and Wet Loose avalanches may not be far behind. You may be more likely to encounter these conditions at higher elevations and on the volcanoes, but pay attention to how the weather is playing out wherever you decide to recreate and adjust your travel plans accordingly.

    (11/27/2020) Pinwheels at Mt. Rainier after rising freezing levels and the sun came out a few days after a storm. [S aspect 5400']

  • Wind Slabs

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

    The wind was certainly potent this week along the crest within the West South, and although we are a few days away from this East wind event, we can’t rule out the possibility of you encountering a lingering Wind Slab on Saturday. We don’t believe there is a lot of snow available for transport at this point, so our focus is on the Wind Slabs formed earlier this week as opposed to the formation of new slabs. Recent observations have confirmed that these slabs are still reactive near the crest. With East wind events like we experienced a few days ago, loading patterns may be different than you are used to, so pay attention as you travel to see where the snow ended up. You can look for smooth pillow-like piles of snow or textured surfaces to help you clue into wind deposited areas to avoid. Although we are calling out areas near the Cascade crest specifically, don't ignore wind deposited snow in other areas of the zone, especially as you ascend in elevation.

    (12/4/2020) A blown-in skin track, forest debris on the surface, and no snow in the trees are all signs reminding us that it was a windy week near the Cascade crest. [Photo: Shane Robinson]

Avalanche Discussion

It has been a battle between warm and cold the past few days in the West South and there have been mixed results. Friday saw the volcanoes surging to over 50 degrees F, while other areas closer to the crest remained relatively cooler. This is a similar pattern as earlier in the week where areas near the crest remained relatively cool due to cold east winds, while other areas not as prone to these winds warmed up. Saturday should see a return to some easterly flow, but don’t expect the winds to be as cool or as strong as earlier this week. There should be plenty of sunshine to go around and any avalanche activity should occur within the recent snow or at the newest interface (11/30). 

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.

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