Bollettino valanghe

Sawtooth & Western Smoky Mtns

Sawtooth Avalanche Center
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Pericolo valanghe

Fri
Alta quota
2 · Moderato
Limite del bosco
1 · Debole
Sotto il limite
1 · Debole
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Non aggiornato — questo bollettino è scaduto 7 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

You could trigger avalanches in wind-drifted terrain at upper elevations. Some drifts overlie crusts and weak faceted snow that formed before the last storm, making wider avalanches possible.  As the sun warms the snow surface, expect natural loose snow avalanches in very steep, rocky terrain directly facing the sun. 

Problemi valanghivi

  • Wind Slabs

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

    Recently formed wind slabs remain a concern in exposed terrain, especially at upper elevations. These slabs buried a variable old snow surface, including wind-hammered snow, crusts, facets, and about anything else you can imagine. The pattern of recent natural avalanche activity has favored slopes on the eastern and western margins of the compass; our snowpack observations indicate those aspects have a crust+facet combination that appears to be more sensitive than other subsurfaces. 

    Look for signs of wind affected snow such as dune-like drifts and ripples on the snow surface. The wind-driven surface textures can be large or small. Sun-induced, loose snow avalanches (see Problem 2 below) have the potential to trigger slab avalanches lower on slopes. Be aware of what's above you. 

  • Loose Wet

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

    Mild overnight low temperatures and rising daytime highs will increase the threat of wet loose avalanches, particularly on E and SE facing slopes that remained cool in the last couple of days. These slides will follow the sun around the compass, beginning on E aspects this morning, moving to S-facing slopes by noon, and finishing on W aspects later in the afternoon. Stability can change quickly; think minutes rather than hours. 

    Loose snow avalanches often initiate in very steep, rocky terrain. Small avalanches can quickly increase in size, particularly in large, funneled, terrain and have the potential to trigger slab avalanches as they travel downslope. Be aware of the terrain above you. You can reduce your risk to this problem by limiting your time spent below very steep, sun-drenched slopes.

Avalanche Discussion

We have a few problems to consider today. Here's a quick review:

Wind Slabs: As described above, you may find small wind slabs that formed over the weekend. They should be relatively small and easy to spot and avoid.  

Loose Snow: Loose snow avalanches are typically divided into dry and wet categories, but there are a hundred shades of grey in-between. If you are skiing or riding in very steep, shady terrain, dry loose slides are on the table. As you wrap onto sunnier aspects, both natural and human-triggered avalanches are possible. Of particular concern are E and SE facing slopes that have remained relatively cool over the last couple of days. These slopes will get a jump start on warming today as overnight low temperatures are nearly 20 degrees warmer than they were yesterday. 

Cornices:  This photo shows some large, overhanging cornice growth near Copper Mountain in the Banner Summit Zone. Cornices are unpredictable beasts and can break much farther from the "lip" or edge than you'd expect. Give them some space, especially if you aren't excited about the prospects of rolling down whatever slope is beneath them. 

All of these problems are simpler to manage than persistent slab avalanches but can be consequential in the wrong terrain. Even small avalanches can have large consequences if they drag you through rocks, over cliffs, or pile you into a terrain trap like a creek bed or gully.

Regioni coperte