Bollettino valanghe

Mount Shasta

Mount Shasta Avalanche Center
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Pericolo valanghe

Thu
Alta quota
3 · Marcato
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

Triggering an avalanche remains possible today. As daytime warming occurs, wet-loose snow instabilities will increase on sunny slopes at all elevations. Wind-drifted snow is present on all aspects near and above treeline. Stay alert for dampening snow surfaces and shooting cracks in wind effected terrain. Use careful terrain management and snowpack evaluation to expand your safety margins, and don’t let your guard down as conditions change.

Problemi valanghivi

  • Wind Slabs

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

    It’s been snowing and blowing across the forecast zone for multiple days. Winds have remained at ideal speeds (light to moderate) for drifting, with plenty of snow available for transport. Over the last 24 hours, winds shifted from southwest to north, redepositing snow onto all southerly aspects. As a result, wind slabs are present on all aspects near and above treeline. Alpine southerly aspects hold the most recently deposited snow, while north and east aspects harbor larger, previously formed drifts. West aspects have been cross-loaded. With improved visibility, it should be easy to see where wind has effected surfaces and identify areas worth avoiding. Remain cautious of leeward slopes and terrain that promotes wind loading. Exercise cautious travel, and use situational awareness and snowpack evaluation to gain an understanding of conditions.  

    Easterly facing wind lip with wind deposited snow below

    Photo: Eric Falconer

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–1.5

    Springtime in the Cascades can lead to rapid wet snow instabilities. A warm weather trend is setting in, and the sun will appear this morning. After fresh snowfall, even just a few hours of direct sunlight can dampen snow surfaces and trigger wet-loose avalanches. This issue can occur at all elevations, but it’s most likely on steep southerly aspects receiving direct sunlight. It's not impossible isolated pockets on northerly aspects may also become unstable. Softening snow surfaces, deep boot penetration, and roller balls are precursors to this problem. If you witness sings of instability, move to shadier aspects and keep your exposer minimal. Time your travel to avoid steep slopes with direct sun and wet surfaces.

    (3/18/2025)

    Roller balls on a sunlit slope. An indicator of rising wet loose instability

    Photo: Cory Beattie

  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely
    Dimensione
    1–1.5

    Yesterday’s observation from Gray Butte found reactive storm slabs up to a foot deep failing on the old snow/new snow interface. While this issue has likely run its course, rising temperatures and sunshine could add weight to any residual slabs and keep isolated areas reactive to triggering. Exercise caution on steep, shady slopes holding more than eight inches of recent storm snow, displaying good slab properties and unstable results from small test slopes. Keep an eye out for any cracking within the snow. 

    Photo: Eric Falconer

    A small pocket of storm slab that failed on the new snow/old snow interface near treeline

Avalanche Discussion

The snowpack has received a large load of new snow and will continue to undergo change in the coming days. These combined factors warrant giving the snowpack time to adjust. A myriad of avalanche problems exist today, and no one wants to end their season on a bad note.

Observations have been extremely limited above treeline throughout the majority of the last few storm systems. We recommend testing the waters slowly until proven otherwise and be prepared to self-evaluate conditions.   

Regioni coperte