Bollettino valanghe

Southern Wallowas

Wallowa Avalanche Center
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Pericolo valanghe

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

In sintesi

New snow and moderate West winds will create touchy wind slabs today.  Winds will increase throughout the day, with gusts into the 40's by nightfall.  Avoid traveling on or around suspect wind loaded slopes.  

Problemi valanghivi

  • Wind Slabs

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

    With fresh snow available for transport, wind slabs will grow in size this weekend.  East-facing terrain will be the most suspect, but if you observe cross-loading, dune-like formations, wind pillows, or shooting cracks these are all signs of wind loading.  Triggering a wind slab could possibly step down to weaker persistent slab layers closer to the ground.  

  • Deep Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–3

    You don't want to mess with this avalanche dragon.  Going into the den of this nasty beast, will not lead you anywhere good.  While the likelihood of triggering a deep persistent slab is low, the consequences are potentially deadly.  This beast is so hard to predict because it can remain dormant for extended periods of time, with no natural or human triggered activity.  You have to remember the bottom of the snowpack consists of weak "sugar" snow, with an avalanche sandwich sitting above it.  This layer was triggered last weekend in McCully Basin, in a popular area known as the "Diamonds."  You can read more here.  

Avalanche Discussion

If you want to dive deeper into the snowpack structure and what we are dealing with in the Northern Wallowas you can read my observation from this past weekend here.   The Structure of the snowpack is one of the biggest factors you should consider.  Right now the upper snowpack is pretty strong but unfortunately rests on top of weak snow.  This leads to a poor snowpack structure, which is why we are occasionally seeing natural and human triggered avalanches with deep crowns.  You will likely get "false positive"  results in your snowpack tests, using compression tests and extended column tests.  Take a look at the photos below, taken last weekend to better understand the poor structure.   For now, your best bet is to use caution, especially above treeline where you may find a trigger point where the snowpack isn't as deep.  Trigger points often are found around rocks, trees, cross-loaded terrain features, where weaker snow exists, or the slab is thinner, making it easier for the weight of a rider to penetrate deeper into the snowpack.  

Regioni coperte