Bollettino valanghe

Blues

Wallowa Avalanche Center
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Pericolo valanghe

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

In sintesi

New snow and wind will build stiff slabs of snow in exposed terrain.  It will be possible to trigger an avalanche underneath corniced ridgelines and in exposed cross-loaded terrain features. Shooting cracks around your equipment, collapsing of the snowpack, and recent avalanches are all clues that the snowpack is unstable.  Enjoyable riding conditions and less risk will exist on wind-sheltered and lower-angled slopes.  

This forecast is sponsored by Eagle Cap Mountain Guides

Problemi valanghivi

  • Wind Slabs

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

    New snow accompanied by wind will continue to drift into stiff slabs that will be sensitive in exposed terrain.  The most likely places to find these wind slabs will be on W-N-E aspects at mid and upper elevations.  Localized wind loading patterns could load additional aspects and mid-slope features.   It will be wise to evaluate any exposed terrain for fresh wind slabs.  Look for clues such as actively blowing snow, a rippled or pillow-like look to the snow surface, cracking around your equipment, and corniced ridgelines.   Avoid areas that harbor fresh wind slabs. Utilize small test slopes that lack consequence to test the reactivity of wind slabs.  

    In wind-sheltered areas that receive 6" or more snow today,  be aware that sensitive storm slabs could exist in terrain steeper than 30 degrees.   The likelihood of this will be greater if the next system arrives ahead of schedule.  

    (12/26/2024) An example of a wind-loaded slope.  Notice the stiff and rippled look of the snow surface with a shooting crack.  

Avalanche Discussion

The series of storms that started on Wednesday morning brought mostly rain to the Blue Mountains.  Freezing levels dropped Thursday night into Friday morning, and 2-3" of new snow fell onto a 6" hard rain crust.  The riding was less than inspiring, but the dropping temperatures into Friday did help to stabilize the snowpack.    Additional snow and blowing snow is forecasted through the weekend, with up to 14-16" possible.   The freezing level is forecasted to stay between 3500' and 4500' through tomorrow.  Expect rising avalanche hazard as we move into Sunday.  

All of the new snow is falling on firm crusts in the Blues.  There is some uncertainty as to how well the new snow will bond to the old slick crust.  It will be wise to jump off your machine and isolate a 1 foot by 1 foot column of snow and pull on the backside of the column to see how well the new snow is bonded to the crust.  If you can pick up the column and it stays together in your hands, you've got a slab.  If it slides easily and produces a smooth, planar surface where it peels away from the crust, you've got all the right ingredients for a slab avalanche.  

Check out the observation from my travels in the Tollgate area yesterday.  

Looking forward and stepping back.

There were no reported avalanches in our forecast area from yesterday,  but with significant additional snow and wind forecasted today through Sunday night, expect an increase in avalanche danger moving into tomorrow.  It will be wise to cultivate a mindset where you are stepping back in your terrain selection.   If you decide to head into the mountains today and tomorrow, it will be paramount to be on your best behavior:  Expose only one person at a time, keep eyes on your partners, and regroup well clear of avalanche path runouts.   Keep clear lines of communication open with your partners, respect the veto power of someone who wants to dial it back, and be clear with your intentions.  

Engage with your backcountry community and forecasters.   Submit an observation here and help us reduce uncertainty.  It can be simple, short, and even anonymous.  Thank you! 

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