Bulletin d’avalanche

Northern Wallowas

Wallowa Avalanche Center
Voir sur la carte

Danger d’avalanche

Sun
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
2 · Modéré
Open full map
Périmé — ce bulletin a expiré 5 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

The new snow that fell on Thursday has been followed by moderate Northwest winds with strong gusts.  These conditions have likely blown the snow into slabs on leeward sides of ridgelines as well as cross-loaded mid-slope terrain features.  Look for signs of windloading such as pillowy rounded features or rippled snow surface, and avoid these areas especially where even a small avalanche could carry you over consequential terain.  At lower elevations, mostly stable snowpack condtions are expected, but if the sun comes out, avoid steep south-facing slopes in the afternoon.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–1.5

    In the Southern Wallowas 5" of new snow fell on Thursday and the Northern Wallowas received 2-3". This snowfall has been followed by moderate northwest winds with stronger gusts.  Last evening wind gusts at the Kip Rand Station were in the 20's with sustained winds in the teens.  These conditions will have loaded the leeward sides of ridgelines with fresh windslabs that sit on a mostly firm snow surface.  Look for wind loading on mostly east to south-facing slopes and evaluate exposed steep terrain that could have been crossloaded by the northwest winds.  Avoid areas where you notice signs of wind loading such as rounded pillowy snow drifts, hollow sounding snow, or snow with a rippled snow texture, especially if these areas are above consequential terrain traps such as cliffs, gullies, or dense trees.  

  • Loose Wet

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

    Daytime warming today could produce shallow wet loose avalanches on mostly south-facing aspects >35 degrees at mid to lower elevations. Look out for signs of wet loose avalanche activity such as pinwheels or roller balls.  If you step off of your sled or out of your boards and sink up to your ankles in wet cohesionless snow, wet loose avalanches are likely in that area and you should avoid terrain steeper than 35 degrees.  

Avalanche Discussion

Lower elevations should provide nice riding conditions with a mostly strong snowpack and 3-5" of fresh dense snow on top.  Utilize hand shears and small test slopes to test for how well the new and old snow is bonded.  The 1/6 layer in the Southern Wallowas was less of a noticable crust, and no significant observations have been made around this layer in the last week.  As always, look for signs of localized instability such as recent avalanches, shooting cracks in the new snow, whumphing or collapsing of the snowpack, or strong over weak snow in your snowpits.  Observations from the Northern Wallowas yesterday indicated strong northerly winds with significant wind transport and loading occuring on south-facing slopes at upper elevations. Avoid steep (>35 degree) E-S terrain at upper elevations where wind-deposited snow could produce wind slabs sensitve to the weight of a rider or skier. Check out this recent observation from Wing Ridge. 

Temperatures have cooled the snow down overnight with a solid refreeze in most locations, but if the sun comes out today southern exposures may become unstable in the afternoon. If  you notice signs of wet loose avalanches on south-facing terrain, stay off of slopes greater than 35 degrees.  

Régions couvertes