Bollettino valanghe

Eastside Region

Eastern Sierra Avalanche Center
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Pericolo valanghe

Tue
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

Consequential avalanches remain possible near and above treeline. Be particularly cautious in areas with more significant snow totals from our last storm. Recent avalanches, shooting cracks, and collapsing are all red flags that indicate the potential for triggering an avalanche. Expect challenging travel conditions today. (Hazard will rise overnight as new snow impacts the forecast area.)

Problemi valanghivi

  • Wind Slabs

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

    Close to a foot of new snow fell along the Sierra Crest over the weekend with fluctuating rain/ snow lines and extreme winds. Clearing skies yesterday gave us the first look at the range since the storm began. While winds continued to move loose surface snow at upper elevations continued slab development has been limited.  Areas of greatest concern include catchment zones near and above treeline, such as the leeward sides of ridgelines, mid-slope depressions, the side walls of gullies, and below convex rollovers. Avalanches will be the largest and most reactive in areas where we received more snow in the northern part of our forecast area, and in areas near treeline where fresh slabs are resting on weak faceted snow.

    Keep an eye out for stiff, hollow-feeling snow and cracks shooting out from your skis or board. These are clear signs you have found a slab. 

Avalanche Discussion

As we continue to take stock of the impacts of our most recent storm system that brought heavy rain and dense wet snow to the forecast area, keep in mind that a substantial amount of water weight has been added to the snowpack. Field observations from the Mammoth area yesterday identified shooting cracks and audible collapsing in the snowpack on isolated terrain features above the rain/snow line near treeline. While we have very limited data, this suggests that triggering an avalanche within the old snow may be possible where a fresh, dense slab rests on weak faceted snow below.  The distribution of this concerning structure is likely isolated to a narrow area near treeline where old, faceted surface snow was spared the worst impacts of heavy rain.  This setup will be most likely on sheltered northerly aspects above 9500' near treeline. Keep a sharp eye out for signs of instability, such as recent avalanche activity, shooting cracks in the surface snow, and collapsing in the upper snowpack. If you notice any of these signs, it is wise to give a wide berth to steep and consequential terrain and areas with shallow trigger points, such as cliff bands and rock outcrops.

If you decide to head out today be ready to contend with a variety of rain crusts, breakable below treeline and more supportable as you gain elevation. In addition, coverage remains thin and riddled with obstacles. Keep in mind that these hard and slick surfaces may make it more difficult to control your speed while navigating thin coverage.

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