Bollettino valanghe

Mt Hood

Northwest Avalanche Center
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Pericolo valanghe

Sat
Alta quota
3 · Marcato
Limite del bosco
2 · Moderato
Sotto il limite
2 · Moderato
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Non aggiornato — questo bollettino è scaduto 4 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

New snow and strong winds will create reactive slabs of wind-drifted snow. These slabs will be most problematic at upper elevations where they may grow quite large and be easy to trigger. Give yourself space from steep wind-drifted slopes.

Problemi valanghivi

  • Wind Slabs

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

    New snow and wind will combine to create reactive wind slabs on Friday. As the day progresses, wind slabs will grow in size and distribution across the terrain, especially in the alpine where they may grow quite large by the end of the day. These slabs may initially not bond well to the slick crust, so they may be quite reactive to a human trigger. 

    Look for these slabs to develop on E-SE facing slopes; mainly on the lee-side of ridges, below cornices, and in the alpine.  

    The wind and blowing snow should be a clear enough indicator for you to choose a conservative travel plan.  Seer around steep slopes being actively wind loaded or showing signs of recent loading. Look for signs such as wind-textured snow, pillow-like slabs, and sharp cornices forming.  If you notice these signs, adjust your travel plans to avoid these potentially dangerous spots. 

    (1/17/2023)

    Shooting cracks - a red flag that should not be ignored.  Avoid wind loaded slopes if you notice signs like this. 

    Photo: Joe Dellaporta

Avalanche Discussion

At the start of your tour, you may only notice a couple of inches of new snow. However, as the morning progresses new snow will pile up, winds will stay strong, and the avalanche danger will be on the rise.  The blowing snow and high wind speeds should be red flags to help you stick to a conservative travel plan.  The bulk of the precipitation and the strongest winds occur in the morning hours; you’ll likely see the greatest avalanche danger during that same time.

This new snow will fall on a patchwork of surfaces. In the alpine, new snow will fall on a variety of slick crusts,  firm wind-board, and sastrugi. At mid and lower elevations, snow will fall on a thin breakable melt-freeze crust or moist snow. The question mark will be how this new snow bonds to the old snow surface. 

If you get out into the new snow, let us know what you see by submitting a public observation!

 

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