Bollettino valanghe

Sawtooth & Western Smoky Mtns

Sawtooth Avalanche Center
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Pericolo valanghe

Thu
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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Non aggiornato — questo bollettino è scaduto 4 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

You are most likely to trigger avalanches where the wind has formed drifts or stiffened the snow surface. The fresh slabs are largest and most widespread in upper elevation terrain and in bowls below steep cliff bands, but you could also encounter them at middle elevations.

Problemi valanghivi

  • Wind Slabs

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

    What is it? You could find fresh wind slabs up to about 18" thick in exposed terrain. The northerly winds of the past 24 hours may have formed both soft and stiff slabs. Wind slabs could overlie weak facets or crusts—especially on SE-S-SW aspects—and be more sensitive to triggering than you might expect.  

    Where is it? Look for wind-blown snow immediately below exposed ridgelines, on the sides of gullies or chutes, and near large terrain features. Wind slabs will be thickest, widest, and most common at upper elevations. In the Sawtooth Mtns, you could find slabs below large cliff bands and on the aprons of chutes and couloirs.  

    How can you recognize it? Cracks shooting out from your skis or sled are an obvious sign of instability. Watch for drifts, dunes, and ripples on the snow surface. Wind slabs can have a smooth, chalky appearance and feel and sound hollow, like a drum. Wind-deposited snow will be stiffer and keep your skis or snowmobile on or closer to the surface.       

    How can you manage it? Managing this problem is simple; steer clear of recent wind drifts and slabs on slopes steeper than about 35 degrees. Hard slabs that keep you or your sled on the snow surface can behave unpredictably, breaking above skiers and riders. 

    (2/6/2023) This small wind slab failed on an ESE-facing slope at 9,100' near McDonald Peak.

Avalanche Discussion

Although not worthy of 'Avalanche Problem'  status, there are a couple of other things to know to minimize the chances of finding trouble in the mountains today:

  • Loose snow avalanches: The mountains closest to Galena Summit (Salmon River Headwaters area) may have received several inches of very low-density snowfall yesterday. Also, the upper foot of the snowpack is extremely weak and faceted on some NW-N-NE-E facing slopes throughout this zone. On very steep slopes approaching 40*, it won't take much to get surficial sluffs moving. These won't be big enough to bury you, but they could knock you over and push you where you don't want to go.  
  • "Rogue" persistent slab avalanches: Triggering a larger avalanche on weak, sugary faceted snow deeper in the snowpack would take some seriously bad luck. To minimize the odds of this scenario, you can avoid very steep (over about 35*) slopes with variable snowpack depths (rocks poking through the snow surface) that also have large, hard wind features that keep you on the snow surface.  

Remember that small avalanches can produce big consequences in the wrong terrain. Before committing to skiing or riding that steep, beautiful-looking line, think about where an avalanche could carry you. Could you get pushed over cliffs, through trees, or into creeks, lakes, or gullies? In "high stakes" terrain, consider the risk versus the reward.

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