Bollettino valanghe

Silver Valley & Bitterroot Mountains

Idaho Panhandle Avalanche Center
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Pericolo valanghe

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

In sintesi

Snowfall and southwest wind overnight continues today, building large new slabs likely to produce human triggered avalanches. With snow levels around 5000’ in elevation, expect rain at most trailheads giving way to significant new snow as you gain elevation. Avalanche danger will increase both through the day and as you gain elevation, as both should increase the size of new slabs and your likelihood of triggering them. Weak layers between the new snow and the early March crust further increase the chance of natural and human triggered avalanches today. Carefully evaluate the snowpack above this crust wherever you travel, choosing low consequence routes or avoiding avalanche terrain altogether.

Problemi valanghivi

  • Storm Slabs

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

    Overnight snow totaled approximately 6” and at least another 6” should fall on moderate southwest wind with strong gusts today. Look for a rain/snow line as high as 5,000’ to create starkly different conditions at higher elevations. Expect greatest snow accumulations and large new slabs at these upper elevations. Wind transport will make these slabs largest on the lee and cross loaded slopes found on the eastern half of the compass rose today. Beneath the new snow, a variety of weak layers above the early March crust were reactive yesterday, contributing to the likelihood and size of avalanches with this storm cycle. Terrain less than 30 degrees in slope angle will be your only true option to avoid today’s growing storm slab problem near and above treeline.

    (3/14/2022)

    Thin storm slab from Sunday, failing on the interface with older snow. N aspect, Sunset and Goose Peak area.

    Photo: Ryan Matz

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–1.5

    Wet loose avalanches below today’s approximately 5,000’ rain/snow line should remain small but could knock you off your feet or machine. Consider the consequence of being pushed downhill by these heavy, wet sluffs in any steep lower elevation terrain today.

Avalanche Discussion

The current storm which may produce 12" or more new snow with 1.5" of SWE will test weak layers above the stout early March crust. Observations in the past week show poor bonding to the crust on all aspects at the same upper elevations receiving heavy new snow today. This poor bonding to the crust includes some areas of sugary facets observed on many aspects and other areas of loose but not quite faceted snow. An interface between this older snow and Sunday’s 6” or so of additional snow was also reactive yesterday. With a new storm slab and no aspects truly lacking  these weak layers, it’s all about choosing low angle or at least low consequence terrain at upper elevations today. Our new slabs over poor snowpack structure may become a persistent problem approaching the weekend, please submit observations of any avalanches or signs of instability you see!

Regioni coperte