Bulletin d’avalanche

Elkhorns

Wallowa Avalanche Center
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Danger d’avalanche

Fri
Alpin
3 · Marqué
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
Périmé — ce bulletin a expiré 6 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

The avalanche hazard will increase with elevation today as freshly formed windslabs will be possible to trigger in the above treeline terrain.  It is not out of the question to see a windslab "step down" and pull out deeper layers of our snowpack.  If you notice red flag conditions such as recent avalanches, recent wind loading, cracking, or whumphing, retreat to lower angle and more simple terrain. 

Problèmes avalancheux

  • Wind Slabs

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

    2 inches of new snow with light to moderate SSE winds will load leeward ridgelines and mid slope terrain features today.  Observers reported that windslabs were unreactive to ski cuts yesterday, and only reported minor sluffing of the new snow.  There were reports of moderate shears within the new storm snow that fell on Monday 1/4.  Observe for fresh wind slab development as they will be rounded hollow pillows and test their reactiveness on small, safe, representative test slopes.  

    WAC forecaster Tom Guthrie's snowpack structure and compression test from 1/6/21. Notice the break in the storm snow failing on diurnal recrystallized grains that formed on Sunday night, before Monday's storm. NE 8400'

  • Persistent Slabs

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

    It remains possible for a person and machine to trigger a deeper avalanche that could fail into the Old November Facets (ONF) that are now 2-3 deep in the snowpack.  The Solstice Rain Crust (SRC) remains as 2 main crusts (each about 1.5" thick) with 1.5" of faceted sugar snow between the two crusts.   The top of the SRC can be found a little over 2 feet (70cm) from the snow surface.  Where thinner and weaker, the SRC will be prone to failing and an avalanche will be able to step down into the ONF layer.  Continue to map the depth,  distribution, and strength of the SRC by stepping off your machine or skis and seeing if you can punch through the SRC.  A probe or ski pole handle poke down into the snowpack will also help you make a mental map of where the SRC is stronger or weaker.  

    Photo: Tom Guthrie. 1/6/21 8400' NE. Note the layer cake style SRC with weak faceted snow in between the harder crust layers.

Régions couvertes