Bollettino valanghe

Mount Shasta

Mount Shasta Avalanche Center
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Pericolo valanghe

Wed
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
2 · Moderato
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Non aggiornato — questo bollettino è scaduto last year. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Warm weather and sunny skies will continue to create unstable wet loose snow on all aspects and elevations, while weakening cornices along ridgelines. Roller balls and penetrable surfaces are precursors to this problem. Minimize time spent on steep slopes and beneath large cornices during the heat of the day. Seek shady aspects or mellower terrain to reduce your exposure. 

Problemi valanghivi

  • Loose Wet

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

    The warmest day of the week has arrived, and the snowpack hasn't refrozen in over 48 hours. With soft, wet snow affecting the backcountry, surfaces may not support a rider's weight, potentially leading to a wet loose avalanche. Steep, southerly slopes that face the sun, especially those with convex shape or funneling features like chutes and gullies, are most likely to avalanche and hold the greatest risk. Radiative heating from rock outcroppings often serves as common start zones and trigger points for wet snow instabilities. Be sure to identify terrain traps and potential hazards before committing to a slope. Expect conditions to worsen as the day progresses. Adjust your travel based on snow conditions, slope aspect, and time of day. These avalanches can be small yet mighty, and problematic in both small and large terrain settings. Avoid slopes showing signs of fresh roller balls, natural point releases, or wet snow higher than your boot cuffs. 

    One way you can evaluate slope stability is by throwing a snowball down hill and seeing if it collects, gouges, or entrains surrounding snow. Also, if you can wring out liquid water from a snowball, that's a tell-tail sign the surface is too wet. 

    Snowmobile triggered D1 wet-loose on east face of Green Butte 

    Photo: Eric Falconer

  • Cornices

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

    With the extended period of above-average warm weather, it's natural to be concerned about the large cornices perched along nearly all ridgelines in the backcountry. There's no way to predict when they might fail, so it's best to give them extra space while traveling both above and below. Keep bare earth or trees between you and the edge, and limit your time beneath them. If traveling by snowmobile, use extra caution, as their weight and speed are far more likely to expose you to this hazard.

    (12/23/2024)

    A cornice near Gray Butte

    Photo: Mount Shasta Avalanche Center

Avalanche Discussion

During a snowmobile tour in the Eddy Mountains yesterday, forecasters observed roller balls and previous natural wet loose avalanches on all aspects, primarily near treeline. On small, inconsequential test slopes, greasy roller balls and penetrable surfaces were consistently present. A crumbling cornice was also observed in one location.

Today, southerly winds will be stronger than yesterday. While this may help keep surfaces cool at higher elevations, don’t rely on this to prevent instability.

The Everitt Memorial Highway and Castle Lake roads are closed.

Regioni coperte