Bollettino valanghe

Central Sierra Nevada

Sierra Avalanche Center
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Pericolo valanghe

Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
2 · Moderato
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Non aggiornato — questo bollettino è scaduto 11 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

MODERATE avalanche danger exists today in the majority of areas on slopes 35 degrees and steeper. Wind slabs are a problem on all aspects in near and above treeline areas. Storm slabs remain a problem on NW-N-NE aspects both near and below treeline. Natural avalanches are unlikely. Human triggered avalanches remain possible.  

Problemi valanghivi

  • Wind Slabs

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

    Strong to gale force ridgetop winds out of the SW yesterday shifted to NE overnight. Ongoing redistribution of snow on the ground today is expected to scour some but not all of the wind slabs formed yesterday and create new wind slabs today. This will allow for wind slabs to exist in some locations on all aspects today near and above treeline. Areas of blowing snow, wind pillows, and sastrugi formations will all be helpful indicators in determining the areas of most recent wind loading.

  • Loose Dry

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely
    Dimensione
    2

    Storm slabs that exist near treeline and below treeline on NW-N-NE aspects are a lingering avalanche problem today. Shaded, wind protected areas with reasonably well developed near surface facets just below the old/new snow interface remain suspect. Keep in mind that these areas will have a significant draw for recreation today so choose slopes wisely. Slope angle is always the easiest data with which to make decisions. The presence or absence of recently buried near surface facets varies widely across the forecast area. Given the overall shallow snow depths associated with the locations of this avalanche problem, quick hand pits remain an effective tool for searching out cohesive surface snow (slab) on top of softer, faceted snow (weak layer).

Avalanche Discussion

Observations made yesterday on Castle Peak (Donner Summit area) revealed the presence of small winds slabs in wind loaded areas near treeline and evidence of storm slabs in open areas below treeline. Skier triggered cracking occurred easily while weighting the edges of wind slabs on test slope features. Wind slabs were not observed to extend very far down slope. Evidence of storm slabs was noted on northerly aspects in areas where new snow had deposited on top of fairly well developed near surface facets. Skier triggered cracking extending from the snow surface down into old snow layers was observed. Click here for photos and more info.

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