Bollettino valanghe

Banner Summit

Sawtooth Avalanche Center
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Pericolo valanghe

Sun
Alta quota
4 · Forte
Limite del bosco
3 · Marcato
Sotto il limite
2 · Moderato
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Non aggiornato — questo bollettino è scaduto 5 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

It's dangerous out there—especially in windier terrain at upper elevations. Continued loading from new snowfall and wind is pushing a weak snowpack to the edge. Numerous natural avalanches were observed yesterday, many large enough to flatten a house. Slides can be triggered remotely—from flatter terrain below, above, and to the sides of steep slopes. 

Problemi valanghivi

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Very Likely
    Dimensione
    2–3

    If you were Santa deciding whether this season's snowpack was naughty or nice, you'd have an easy answer. Lurking beneath a charming (and powdery) exterior is a dangerous character flaw—weak October snow buried beneath a dense 3-4' slab. The facet layer is most prevalent on mid and upper elevation shady slopes (NW-N-NE-E facing).

    Our snowpack's true nature has been revealed a number of times this winter, including yesterday. Partial clearing skies revealed numerous large to very large avalanches that released as a result of Thursday's storm. Perhaps most notable is a huge avalanche on Galena Peak (in the Galena Summit & Eastern Mtns zone)  that would have destroyed your truck, the garage it was parked in, and the neighborhood you live in. Numerous large to very large avalanches occurred in the neighboring Western Smokys (photo) and Sawtooths (photo, photo). Continued loading due to wind last night and snowfall today will keep our dangerous snowpack on the brink. 

    While the snowpack deserves a few lumps of coal, you deserve some powder skiing and riding. Luckily for all of us that have been good boys and girls this year, there is incredible powder conditions to be enojyed in low angle terrain. Sticking to gentler slopes is the primary way to avoid the persistent slab, but also avoid being below steeper terrain since the possibility of remote triggering is real.

    (12/24/2021) Very large natural avalanche on "Marshall Slide" in the Sawtooths, on the shoulder of Williams Peak, above the Marshall drainage. This avalanche appears to have failed in the October facets deep in the snowpack. NE-aspect at 9,000'.

  • Storm Slabs

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

    This extended period of stormy weather as delivered enough new snow and wind  to make triggering an avalanche a possibility even on slopes that lack the October weak layer. Yesterday, numerous storm slab avalanches were observed in the neighboring Sawtooths—most of these occurred in steep, wind affected terrain. The storm snow had a short chance to stabilize yesterday, but winds blew at moderate to strong speeds overnight and more snow is in the forecast today. 

    What this means is that we need to use caution on all steep slopes—even southerly-facing terrain where the persistent weak layer (Problem #1)  is absent. Storm slab avalanches are most likely in exposed, wind affected terrain at mid and upper elevations.

    (12/24/2021) Large natural avalanche on "Tortilla Slide" in the Sawtooths, on the shoulder of Williams Peak. E-aspect at 9,100'.

Avalanche Discussion

Ready for some Christmas cheer?

Here’s a Christmas poem unraveling the mysteryOf how today’s snowpack relates to the weather history.

Storms in late-October came in with a bangThen a warm, dry November made us say “dang”!The snowpack was off to such a promising start But after a long dry spell, things fell apart.

Sunny slopes and low elevations turned to dirt and sageInstead of skiing and riding, biking was the rage.Where snow lingered up high and in the shadeA nasty weak layer of crusts and facets was made.

As we were all beginning to feel like chopped liver,Our area was targeted by an atmospheric river!Over several days it dumped 3-5 feet of snow;And when it stopped, there were avalanches fo’ sho’.

A storm this week touched off the snowpack once more;Visibility yesterday revealed avalanches galore.Through the holiday weekend more snow is forecast,And the grinch who stole Christmas says High danger will last.

If you head for the backcountry today, make a vow:This Christmas I’ll enjoy some low-angled pow!

Be sure to catch up on this week's conditions in our latest Weekend Update.

Regioni coperte