Bulletin d’avalanche

Northern Wallowas

Wallowa Avalanche Center
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Danger d’avalanche

Mon
Alpin
3 · Marqué
Limite forestière
4 · Fort
Sous la limite
3 · Marqué
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Périmé — ce bulletin a expiré 2 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Heavy rains and warming will likely trigger many natural avalanches today throughout the mountains on slopes greater than 30 degrees.  If there is a rapid change event to trigger a deadly 2-4' thick slab involving our January weak snow, this is it.  This is a good day for indoor activities, but if you do travel outside, do not stop yourself or your vehicle under steep roadcuts or snowy roofs.  We recommend avoiding avalanche terrain.  

This forecast is sponsored by M. CROW – M. Crow

Problèmes avalancheux

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Very Likely
    Taille
    1–2.5

    Rain on snow will cause widespread avalanching.  Expect to see this on roadcuts and some lower elevation terrain that may not slide often. 

    Wet loose avalanches typically start in terrain steeper than 35 degrees, and while they travel slowly, they are very dense/destructive and can travel long distances into the flats.   

    With this volume of rain, Wet Slab avalanches are possible if liquid water percolates down to a crust or bed surface.  

    (3/18/2023)

    D1.5 wet loose avalanche observed at 8200' on SE face of Van Patten Butte. Likely ran on 3/17. Toe of debris pile was 2-3' deep and slide ran 100 yards.

    Photo: M. Hatch

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    2–3

    A rapid input/change of rain and warming will increase the likelihood of a very large and deadly persistent slab awakening.  This weak layer has been slowly gaining strength, but an additional load on the slab above it will test it.  If it's going to slide, it would be today.  

    (2/9/2023)

    Photo of a persistent slab avalanche in the Southern Wallowas.   

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2

    If for some reason you brave the high snow line and venture into the alpine, look for textured, rippled or unusually smooth surfaces.  Feel for hollow or drum-like sounds, or snow that suddenly supports your skis, board or machine.  Avoid these features in avalanche terrain.   But take photos!

    (2/20/2025)

    D2 Windslab Avalanche released naturally likely on 2/19.  Note the wind-loading just below a corniced ridgeline. 

    Photo: Victor McNeil

Avalanche Discussion

Another 1" of rain up to 8000' will create dangerous avalanche conditions on all terrain greater than 30 degrees.  Some of these slab avalanches could be 2-4' thick and unsurvivable. 

If you do brave the sogginess, avoid all areas where avalanches can start, run, or stop. This includes openings in the forest well below large steep alpine slopes.

It's been great to see all of the recent observations.  Thanks to a member of the public who submitted a roadside natural slab on the Anthony Lakes highway last week.   Road or spotting scope photos are excellent.  Add value to your forecast.  Submit an observation here.  

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