Bollettino valanghe

West Slopes South

Northwest Avalanche Center
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Pericolo valanghe

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

In sintesi

Expect conditions to change throughout the day as temperatures warm and precipitation continues. With several overlapping avalanche issues and a weak snowpack, this is a good day to keep it simple. Use terrain where you can easily identify and avoid steep avalanche slopes.

Problemi valanghivi

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–1.5

    Near and just above the rain-snow line, wet snow could easily slide downhill. These avalanches could run the entire length of the slope if the slide travels on a crust or older wet snow. You may see rollerballs, but the easiest clue will be wet, mushy snow deeper than your ankle. 

    Even though this issue is often easy to anticipate and manage, these slides have a tendency to grab you and not let go. That means you’re heading wherever they take you, like into a creek or over a cliff. Be leery of steep slopes above higher consequence terrain. 

    (2/24/2026)

    Example: Small natural wet loose slides below rocks from earlier this winter. 

    Photo: Andy Harrington

  • Storm Slabs

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

    Precipitation totals from this storm aren’t super impressive, but the new snow has already shown a tendency to fail. More snow by Friday morning and warming temperatures could turn it even more up-side-down and allow these slabs to trigger easily. Expect avalanches to be larger in wind loaded terrain and near the volcanoes where more snow has fallen. 

    You may see an avalanche on any steep slope, but these slides will be more likely on convex rollovers, in unsupported terrain, and in wind affected areas. Slabs may fail with the storm snow or just above the new-old interface.

    (3/5/2026)

    Example: A natural storm slab avalanche from the Snoqualmie Pass zone on Thursday. 

    Photo: Northwest Avalanche Center

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1.5–2.5

    How will the underlying persistent weak layers react to the additional precipitation and warming? That’s the million dollar question. It's very hard to say. We haven’t seen recent avalanche activity on these layers in about a week. If water manages to reach them from rain, that could cause these weak grains to trigger more easily. Or, the warmer temperatures could help them heal. 

    Unfortunately, there’s no quick test or observation to answer this question. Instead, giving them space during this time of additional uncertainty could be prudent. Relatively smaller storm slabs and wet loose slides could act as a larger trigger, waking these deeper layers back up on some slopes. 

    (3/5/2026)

    A snowprofile in the Crystal area highlighting the most recent snow, a developing crust in the upper snowpack, and our persistent weak layer down below.

    Photo: Andy Harrington

Avalanche Discussion

We just can’t seem to shake the mild temperatures. After a dip in snowlevels bringing snow to most trailheads, rain is once again creeping back up the hillsides. It should reach near the middle elevations by Friday afternoon. Storm totals range from 4-10 inches, with Mt Saint Helens likely stacking up 12-18inches. Further south, stronger winds likely formed hard slabs on Mt Adams and Mt Saint Helens. Check the Mt Hood forecast for more information on these wind slabs. 

Persistent Weak Layers

  • Generally above 5000ft
  • 2/13 Surface Hoar/Facet: Northerly aspects. 4-6 inches above the 2/7 crust. 
  • 2/7 Crust: All aspects. Facets above and sometimes below this 1-2 in brittle crust.
  • Layers may be moist to wet with rain. 

There’s no way around it. Coverage is thin across the board. This is doubly true at lower elevations and on sunny aspects. Plan extra time to deal with the added travel challenge. 

Regioni coperte