Bollettino valanghe

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Wallowa Avalanche Center
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Pericolo valanghe

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

In sintesi

At mid and lower elevations below yesterday's snow line, lingering wet-loose avalanches could occur in wet and unconsolidated snow.   You are likely to trigger avalanches occurring in new and wind-blown snow today in exposed terrain at upper elevations.   These will be especially sensitive where the new snow sits above a firm crust.  Look for obvious clues to instability such as recent avalanches and cracking of slabby snow under your boards or machine. 

This Forecast is Sponsored by: The Wallowa County Gamblers Snowmobile Club

Problemi valanghivi

  • Loose Wet

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

    Below yesterday's snow line, a rain-on-snow event occurred, weakening the strength of the upper snowpack.  Look for signs of recent wet loose activity in steep terrain on all aspects at lower elevations.   There should be a stabilizing trend of this avalanche problem as the temperature drops into the weekend.   You can use small inconsequential test slopes to push some wet snow and see how easily it entrains more unconsolidated sloppy snow.   Avoid riding above terrain traps such as cliffs, gullies, and creeks where even a small wet loose avalanche could pile up enough snow to bury or injure you.  

    Wet Loose avalanche debris following a rain event in the Southern Wallowas (2/26/25)

    Photo: Caleb Merrill

  • Wind Slabs

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

    In terrain exposed to the wind (above the snow line), snow has been blown into dense drifts or slabs of snow that will likely remain sensitive today.  Large avalanches could be triggered in exposed terrain at upper elevations.  These avalanches will run fast and far where the bed surface is a firm crust.  Look for clues to wind loading such as a rippled or stiff snow surface, cracking around your skis or under your machine, and fresh cornice development along ridgelines.  Use small test slopes with little consequence to test the reactivity of fresh wind slabs.  

    In wind-sheltered areas, storm slabs are likely to be less sensitive than wind slabs today, but you should remain vigilant.  Yesterday, during the peak intensity of the precipitation during mid-day, storm slabs were easily intentionally triggered in any terrain over 30 degrees.  See photos below (from the Western Wallowas).  

    (3/12/2025)

    Rippled snow texture was a good telltale sign of recent wind loading. 

    Photo: Caleb Merrill

Avalanche Discussion

The High Ridge Snotel site received 1.1" of precipitation in the last 24 hours.  Unfortunately, most of it fell as rain.  The Milkshakes snotel picked up 2" of snow with the remainder precipitation recorded as rain.   The rain-on-snow event has likely destabilized the upper snowpack.  The freezing level looks to continue to drop today, and while a cooling trend is ongoing, the chances of triggering wet avalanches will decrease.   However, stabilization of a saturated upper snowpack can be slow to occur.   If you find yourself in wet sloppy snow, avoid steep terrain above terrain traps and stay out from underneath steep slopes.  Look for signs of recent wet snow avalanches, pinwheels or rollerballs, and rain runnels in the snowpack (see photo below).   

Yesterday in the Western Wallowas, storm snow remained touchy in any terrain greater than 30 degrees in steepness.  Observers intentionally triggered numerous avalanches 4-6" deep through ski cutting.  These avalanches propagated widely across terrain features and ran fast and far on a firm crust bed surface.   Winds were moderate to strong all day yesterday and into the evening.  This has blown the snow into deeper slabs that will remain sensitive to the weight of a rider today.  

It is time to take a step back in your terrain selection.   To decrease your odds of getting caught in an avalanche, stick to simple terrain under 30 degrees and avoid recently wind-loaded terrain features.  If traveling in avalanche terrain, remember good travel and communication protocols:  Expose only one person at a time, keep eyes on your partners, and regroup well clear of avalanche path runouts.   Keep clear lines of communication open with your partners, respect the veto power of someone who wants to dial it back, and be clear with your intentions.  

Engage with your backcountry community and forecasters.   Submit an observation here and help us reduce uncertainty.  It can be simple, short, and even anonymous.  Thank you! 

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