Bollettino valanghe

Galena Summit & Eastern Mtns

Sawtooth Avalanche Center
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Pericolo valanghe

Sat
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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Non aggiornato — questo bollettino è scaduto 5 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Triggering a large avalanche remains a possibility. You can greatly reduce your risk by steering clear of very steep, rocky, wind-affected slopes.

Problemi valanghivi

  • Persistent Slabs

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

    It's been two weeks without an avalanche, substantial loading, or notable snowfall. So why are folks just now cautiously "stepping out" into shady, consequential avalanche terrain?

    • The Weak Layer: Weak, sugary faceted snow exists near the ground on many upper elevation slopes as well as shady NW-N-NE-E facing slopes at middle elevation. This layer is widely distributed and is not strengthening quickly in this zone.
    • The Slab: The 2.5-4 foot thick slab above the weak snow is thick enough to produce large avalanches that could bury people but thin enough that skiers and riders can impact the weak layer and possibly trigger slides. 

    The nature of a persistent slab problem is in the name. This problem will take time to heal and will require patience to manage. Triggering a large, persistent slab avalanche is still on the table. To reduce the chances of finding trouble, avoid  "prime time" slope angles (35-45*) in rocky, wind-affected terrain (see photo). 

Avalanche Discussion

Yesterday's small amount of snow and moderate wind wasn't enough to change the big picture. The persistent slab problem described above sits head-and-shoulders above the ones listed below. That said here are a few additional considerations when planning a day in the bigger peaks:

  • Slope Angle: Avalanches are most likely on "prime time" slopes, those around 35-45* in steepness. 
  • Wind Slabs: Be on the lookout for a fresh set of thin, isolated wind slabs. You're most likely to encounter this problem in upper elevation terrain of the Smoky Mountains. Fresh slabs are likely to be very small but have the potential to knock you off your feet. These as well as older, weathered slabs will be most sensitive where they rest above polished icy surfaces or pockets of weak, faceted snow. Watch Ben's video to see real live snowflakes falling from the sky!
  • Loose Snow: A fresh blanket of light dry snow will be easy pickings for the sun. Expect to see small loose snow avalanches on very steep slopes that face the sun. These slides will be most likely in the Smokys. They often start near rocks or the base of a warm tree and fan out and collect snow as they go.
  • Cornices: Cornices are abnormally large for January. Look out for yawning cracks that form when these blocks of snow peel away from steep ridges. Continue to give these unpredictable features the respect they deserve.

Yesterday's snow may be the last we see till February and our list of relatively low probability avalanche problems isn't likely to change. While the odds of triggering a large avalanche are decreasing, playing in the mountains comes with unavoidable objective hazards. Even small avalanches can have big consequences in larger, more complex terrain. Considering the consequences of an avalanche before riding a slope is a good way to keep your ambitions in check. 

Regioni coperte