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

New snow accumulating through the day and strong shifting winds will increase the avalanche danger. As an artctic front moves in this afternoon, we will see snow accumulations of 6-10" today. Ridgelines and open terrain at treeline and above will experience slab development, cross loading will be present on all slopes as the wind changes from SW-E-NE. Avoid steep, open terrain and stick to low angle trees to find the safest riding and best snow conditions today.

Problemi valanghivi

  • Storm Slabs

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

    As the main event of the storm moves in today, snow totals ranging from about 6-10" will likely create a storm slab problem. As snow totals build through the day, triggering an avalanche will become likely .  Moderate to strong winds will continue to blow out of the southwest, but will transition to primarily east and northeast in the afternoon. With transporting winds blowing all around the compass, you're likely to see wind slab development on all open slopes today. Expect to find wind loading and cross loading on aspects that typically don't get as affected by the wind. Now is a good time to dial back those terrain choices by avoiding slopes steeper than 35 degrees and wind loaded terrain. 

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1.5–3

    Facets around January’s Lucky Friday layer are still a concern. Now buried 1-3’ deep, depending on location, a slide on this layer is a low likelihood, high consequence scenario. Recent stability tests have shown this layer to be stubborn, but the variance in reactivity makes it unpredicatable and concerning. I believe it has the potential to propagate in the right situation, on big slopes near trigger points where the snowpack is shallow.

Avalanche Discussion

 On Monday, February 19th we toured out to West Willow Peak. The whole tour felt quite warm as we experienced temps hanging around the 30's. Daytime snow accumulations under delivered, but we did experience winds blowing through the day, and building in the afternoon. Even at elevations around 6000' the snow felt dense and heavy.

We noticed a thin rain crust developing around treeline, and becoming more prominent as we gained elevation. At elevations above 6,000', this rain crust was more pronounced and could become a potential bed surface for the new storm snow. This rain crust will become more of a problem at upper elevations on all aspects. With this potential weak layer getting buried today, it is a good time to really consider what terrain you're exposing yourself to and dial down those terrain choices. Strong winds Monday night and Tuesday will only add to the avalanche hazard. 

Looking ahead, the cold front moving in this afternoon will persist through Wednesday and Wednesday night. Winds will slightly decrease during the day and ramp back up tonight. With these rapid weather changes, consider giving the snowpack time to adjust and bond before stepping out into consequential terrain. 

 

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