Bollettino valanghe

East Cabinet Mountains

Idaho Panhandle Avalanche Center
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Pericolo valanghe

Wed
Alta quota
4 · Forte
Limite del bosco
4 · Forte
Sotto il limite
3 · Marcato
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Non aggiornato — questo bollettino è scaduto 6 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Strong winds and fresh snow have created hazardous avalanche conditions at Treeline and above. Avoid  riding or travelling in terrain over 30 degrees in steepness through Wednesday. Wind slabs will be prevalant and easily triggered on North and East aspects. Fresh storm snow at upper elevations will also be easy to trigger and may have the potential to step down to our deeper weak layers that linger across the area.

Problemi valanghivi

  • Storm Slabs

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

    Since Sunday morning the East and West Cabinets have received over 3" of snow water equivalent (SWE).  This moisture has fallen as a rain-snow mix below 5,000 feet, above this elevation it will be all snow and lots of it! This new snow came in on the warm side with lots of wind, anticipate it to form dense and sensitive slabs that will be easily triggered through Wednesday. With the drop in temperatures last night lower elevation snow pack will be less sensitive. In the Purcell Range there will be significantly less snowfall and storm slabs will be much thinner.

  • Wind Slabs

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

    The winds have been cranking out of the Southwest since Sunday. With fresh snowfall available for transport you can expect to find very touchy windslabs below ridgelines on northeasterly aspects. Any chute or gully like feature in steep terrain will also be likely to harbor dense and sensitive windslabs and should be avoided. Yesterday we  remotely triggered a windslab on a NE aspect below the ridge on Flatiron Mountain. This slab tapered in thickness from about 12" deep to 20"+ on the thick end. It was very dense, hard and released on a layer of surface hoar with a dense bed surface. See video below.

     

  • Persistent Slabs

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

    Persistent weak layers in the snowpack continue to, well, persist I guess. We have buried surface hoar and weak, sugary snow near the January 13th rain crust across the area. This problem is most concerning in the Purcells were the snowpack is weak, thin and proving to be pretty reactive in stability tests. With fresh snow loading these weak layers they will increase in sensitivity as they adapt to a fresh load of snow.  Tests in the East and West Cabinets have been giving us less reaction and leading me to believe it wasn't as much of a problem. Turns out, I may have been wrong. See adjacent photo.

     

    Photo taken this past weekend on Smith MT. in West Cabinets. Remotely triggered by 2 of Troys most entertaining snowmobilers. Crown is close to 3 feet in depth.

Avalanche Discussion

Mark Twain wisely said, "It's not what you don't know that often gets you in trouble, it's what you know for certain that just ain't so."

I go into the mountains with a general impression of what the hazards will be and seek to prove myself wrong, with a persistent weak layer across a large area I often find that this tricky animal eludes me into thinking I know more than I actually do. So, play a conservative game out there be a little more curious about the conditions and consider the possibility that you may be wrong about the conditions. I have seen quite a few slides triggered in pretty tame looking terrain this year. The persistent slab issue gets redundant; but, survival in avalanche terrain right now is a game of patience.  Keep your eyes on the long game friends.

Regioni coperte