Bollettino valanghe

Eastside Region

Eastern Sierra Avalanche Center
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Pericolo valanghe

Thu
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

It may be possible to trigger a consequential avalanche in terrain where the wind has deposited slabs of stiffened snow near and above the treeline. Wet Loose avalanches will also be a concern in steep unsupported terrain on solar aspects. Keep an eye out for signs of instability today, such as shooting cracks in surface snow and recent avalanche activity. Be ready for conditions to change throughout the day. 

Problemi valanghivi

  • Wind Slabs

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

    Mostly light winds yesterday led to minimal redistribution of loose surface snow. As winds shift back to the southwest today and increase in speed, we could see fresh wind deposits near and above treeline. This means that wind slabs could range in size and sensitivity. Fresh deposits will be more reactive and relatively small, while older wind deposits will be larger and are likely to be stubborn.  Exercise caution near ridgelines, in gullies, and on steep leeward slopes. Wind slabs may appear rounded and textured or feel hollow underfoot. Recent avalanches, shooting cracks, and collapsing in drifted snow are warning signs to dial back your slope angle and stick to wind-sheltered areas.

    Photo: Steve Mace

    3/18/2025

    Shooting crack in reactive Wind slabs near treeline - Mammoth Area

  • Loose Wet

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

    The strong March sun overpowered relatively cool temperatures yesterday. Roller balls and a few small Sluffs of wet snow were observed on solar aspects as surface snow warmed. As the sun comes out and temperatures rise today, Wet Loose avalanches will become increasingly likely. 

    Expect areas of concern to move around the compass rose throughout the day. Easterly aspects will warm first as the sun comes out this morning, followed by southerly and westerly aspects as the sun moves across the sky. Rollerballs or pinwheels and increasing boot penetration are signs of instability that often foreshadow larger point-release avalanches. Radiators such as cliffbands, rock features, and confined couloirs can trap heat and exacerbate the effects of warming. Wet Loose avalanches often fail from a single point and entrain heavy snow as they move downhill. The best way to manage Wet Loose avalanches is to ascend slopes while they remain cold and be off of steep slopes before surface snow becomes wet and unconsolidated.

    (3/18/2025)

    Roller balls and small, Wet Loose sluffs on a solar aspect below treeline. - Mammoth Area

Avalanche Discussion

The most notable change to the forecast is the removal of our Persistent Slab problem. Targeted snowpack evaluations continue to highlight poor structure in some areas.  Over the last week, active weather has brought over 3" of water to favorable areas, with no new persistent slab avalanches or signs of instability reported. While the structure is concerning in some parts of the forecast area, initiating a failure on these buried weak layers is unlikely. When in doubt, you can limit your exposure to triggering a very large slab avalanche by choosing simple, low-consequence terrain in areas with a deeper and uniform snowpack.

Spring officially starts tomorrow, and the weather certainly seems to agree. As the sun gets higher in the sky and we shift into a generally warmer temperature regime, we expect more predictable avalanche conditions focused on surface instabilities. Keep in mind that our snowpack is in a state of transition following our last winter storm. While recent wind deposits are gaining strength, wet surface sluffs are becoming more likely. Monitor conditions closely throughout the day and be ready for things to change quickly.

 

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