Bollettino valanghe

Central Sierra Nevada

Sierra Avalanche Center
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Pericolo valanghe

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

In sintesi

Additional snow and strong winds could form areas of concern where wind blown snow exists.  These wind slabs could form near and below ridges, in gully features, and in open terrain where wind transport has occurred.  Sluffing within the new snow and storm snow instabilities could also occur today.  Look for signs of unstable snow and avoid steeper terrain if you see signs of instabilities. 

Problemi valanghivi

  • Wind Slabs

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

    Continued snow and SW winds will keep wind slab avalanches possible for today.  SW winds have varied throughout this storm cycle over the last few days and increased in speed overnight along the higher ridges and peaks.  Moderate to large amounts of snow are available for wind transport where winds have increased.  Large cornices could continue to be fragile and exist above slopes where these wind slabs have formed.  Human triggered wind slab avalanches are possible today and could be large in size.

    Look for evidence of previous or current wind transport and scouring.  Blowing snow, cornice development, and snow surface scouring will be clues as to where these wind slabs may exist.  Give wide safety margins to steep wind loaded slopes and areas below large cornices.

    (2/2/2024)

    This rock was only 150ft away but we could hardly see it or the cornice next to it due to blowing snow. We quickly dropped back below treeline.  Upper Blue Lake, Carson Pass area.

    Photo: SAC

  • Loose Dry

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

    Low density snow and cold temperatures will continue dry loose sluffing on steeper slopes.  These sluffs could run long distances and entrain more snow on bigger terrain.  In some areas, the recent storm snow could slide on the previous firm old snow surface crust.  These sluffs are expected to be mostly small in size, but could be large enough to knock a person over or push them into rocks, cliffs, or terrain traps. 

    (2/2/2024)

    Long running loose dry activity.  Cathedral Peak, Fallen Leaf Lake area.

Avalanche Discussion

A large and powerful storm with good spillover into the eastern side of the forecast region is now expected on Sunday through Monday.  The persistent weak layers that formed during our early winter season near the base of the snowpack are still present in areas that have a shallow and weak snowpack-mainly along the eastern side of the forecast region.  These weak layers have been dormant for some time, but have shown some evidence that they could reactivate with a large loading storm event.  An isolated deep slab avalanche could become possible during this next storm event-starting Sunday.  Any avalanches associated with these deep weak layers would be wide and very large, involving most of the existing snowpack in these areas where these conditions exist.

Regioni coperte