Bollettino valanghe

Northern Wallowas

Wallowa Avalanche Center
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Pericolo valanghe

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

In sintesi

Persistent weak snow lingers in the snowpack.  Winds have formed sensitive slabs of stiff snow along ridgelines and exposed terrain.   Human-triggered avalanches remain likely above 8000 feet, especially where stiff drifts of wind blown snow rest above weaker snow.   Avoid freshly drifted snow on exposed slopes and near ridgelines to reduce your chances of getting caught up in a large avalanche.  

Today's forecast is sponsored by: Anthony Lakes Mountain Resort

Problemi valanghivi

  • Wind Slabs

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

    Reports from yesterday in the Northern Wallowas indicated strong winds moving snow into stiff slabs at upper elevations.  One natural wind slab was reported along South Ridge of Wing Ridge yesterday with additional reports of cracking of the wind blown snow along exposed terrain.  

    Wind slab avalanche problems may be present lower on slopes than you might expect if wind speeds reach the forecasted values.    Mid-slope terrain features may also become cross-loaded.  

    Look for clues to wind slab development:  A stiff and rippled texture, snow stripped terrain upwind of loaded slopes, cornice development, and fresh dunes of snow drifts.   Avoid wind-loaded slopes steeper than 30 degrees in steepness.  

    (2/21/2026) Photo: Wallowa Avalanche Center

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2.5

    The Wallowas have received over 2' of snow since February 8th, ending the January drought and burying a layer of facets. These facets remain reactive in snowpack tests and observers have reported collapsing (or whumpfing) in isolated areas.  These grains are less of a concern in areas where thick crusts formed on the surface before February 8th.

    Surface hoar was also observed up to 8400' in the Southern Wallowas before the Valentine's Day storm, specific to sheltered terrain facing north and east, and has been found buried intact in a few locations. 

    We have developed a complex snowpack in sheltered, shady terrain.  Managing this instability will require patience and investigation.    There is a high degree of spatial variability around the structure of our snowpack concerning the Valentine's day buried surface hoar and the thickness of crusts that cap the January facets.   

    Remember: this forecast is for a large area of terrain, and specific nuances in the snowpack may vary from drainage to drainage.  It is recommended to investigate the snowpack structure on a slope scale before committing to consequential avalanche terrain.  

    Persistent slabs are notorious for giving little to no feedback. Tracks on a slope do not indicate the absence of a problem.   As we increase the stress on the snowpack through wind-blown snow, it will remain possible for a smaller wind slab avalanche to step down into older and deeper persistent weak layers.   

    If you have uncertainty about managing this problem, the best advice is to select more conservative terrain less than 30 degrees in steepness with no overhead avalanche paths.  

Avalanche Discussion

The likelihood of triggering a large destructive avalanche will increase as you enter terrain where a wind slab has formed over weaker snow.  

Snowpack struture can change from drainage to drainage. This can influence the complexity of managing our persistent slab problem.  Remember that elevation bands are not definite boundaries; for example the interior typically receives more snow and less wind than the perimeter. Use the forecast as a starting point, but continue assessing conditions as you travel.    

Careful snowpack evaluation and conservative decisions will be critical in the coming weeks, given the continued possibility of overlapping new (wind and storm) and old snow problems (buried surface hoar and/or january facets). Choosing low-consequence terrain will be the key to successfully managing these hazards. 

In addition to the wind slab and persistent slab problems, it will also be possible to find small dry loose avalanches in sheltered terrain that is steeper than 35 degrees in steepness.  Manage your sluff and consider the consequences of a small loose snow avalanche if you happen to be above terrain traps.  

If you are out in the mountains, please send us an observation of what you saw. All observations are noteworthy and greatly help the forecasters. If you don't want everyone to see where you went you can set it to private so only the forecasters will see it. 

Beacon Parks: Thank you to everyone who helped establish the beacon training park at Anthony Lakes (across from the ski lift on Mud Lake) and near the warming shelter at Salt Creek Summit snopark outside of Joseph, OR. These are free tools that we should all take advantage of.  

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