Bollettino valanghe

Mount Shasta

Mount Shasta Avalanche Center
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Pericolo valanghe

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

In sintesi

Heightened avalanche conditions exist near and above treeline for wind deposited snow on south and east aspects, with further loading from west and northwest winds. Observe for blowing snow, wind lips, and cornices, highlighting areas of concern. Select non-consequential terrain and manage exposure to best mitigate this problem.

Problemi valanghivi

  • Wind Slabs

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

    West and northwest winds have made quick work of crafting drifts and loading leeward pockets of terrain on south and east aspects near and above treeline. Today, finding instabilities on or near wind loaded features, such as ridgelines, sidewalls of chutes and gullies, or convex slopes, won't be difficult. Wind deposits often present themselves as lens-shaped, or dune-like, with rippled or wavy snow texture. Blowing snow and cornices will point you in the direction of wind loading. 

    Yesterday, wind lips and cornices were easily triggered, causing subsequent avalanches on the slopes beneath. While relatively small (<D1), this feedback illustrates the potential on a larger scale. With dry snow in the mountains, cold temperatures, and moderate wind speeds, the sensitivity of the problem will likely increase with the incoming storm. Stay tuned for red flags of avalanche danger and heed caution to steep, exposed terrain that displays signs of wind effect. Seek avoidance of this problem by traveling on windward aspects, scoured surfaces, or slopes less than 30 degrees.

    Cornice collapse and subsequent avalanche on a leeward slope above treeline in the Old Ski Bowl, easterly facing 

    Photo: Eric Falconer

Avalanche Discussion

Yesterday, forecasters rode into the Old Ski Bowl to assess conditions after last night's storm. It was a beautiful day, with 3–5 inches of new snow below treeline, and 5–8 inches above. Signs and symptoms of wind effect were evident. A small natural avalanche was observed off Green Butte Ridge into the Old Ski Bowl that likely occurred early yesterday morning. Overall snow conditions and coverage drastically improved from the day prior from being wind scoured and firm. Read more on yesterday's outing HERE.     

Santa and the reindeer must have had a chilly night, with below freezing temperatures for all elevations. Today's cold temperatures, paired with wind chill, and an incoming storm can catch even the most experienced travelers off guard. If exploring or adventuring into the backcountry, be prepared. Always carry the essential avalanche safety equipment and survival tools, as getting lost or stranded without means of shelter, light, food/water, or communication would be tragic.

Wishing everyone a safe, healthy, and happy holiday — Merry Christmas!    

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