Boletín de aludes

East Slopes North

Northwest Avalanche Center
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Peligro de aludes

Sat
Alta montaña
2 · Moderado
Límite del bosque
2 · Moderado
Bajo el límite
1 · Débil
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Desactualizado: este boletín caducó last year. Estás viendo condiciones pasadas, no el boletín vigente.

Lo esencial

Continue to put a large buffer between you and terrain connected to large avalanche paths on the northern half of the compass.  The likelihood of triggering a persistent slab avalanche may be slowly ticking down, but the severity should still dictate how you travel.  Watch for shallow areas of drifted snow at upper elevations and small wet loose avalanches on very steep sunny slopes. 

Problemas de aludes

  • Persistent Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Possible
    Tamaño
    2–3

    Don't go to sleep on this snowpack.  Put plenty of space between you and steep open slopes on the north side of the compass. From late February through the first few days of March, multiple very large and widely propagating avalanches were reported. In two separate involvements near Harts Pass, riders were buried and in one incident, one person was killed. 

    The January Drought Layer is about 3 feet below the surface near and east of Washington Pass.  This layer is deeper further west of Washington Pass and may be more difficult to trigger.  Aside from the widespread recent avalanches, you may not see other signs of instability.  

    Avalanches may need a larger trigger like a snowmobile or cornice to impact deeper layers.  These avalanches could break across entire slopes, run long distances, and even reach valley bottoms. The only way to deal with this issue is to be diligent and avoid this terrain.

    (2/28/2025)

    A large avalanche near Hart's Pass that caught 2 snowmobilers and resulted in one fatality on February 28th. 

    HS-AM-D2.5-R4-O. Cone Mtn, NE, 6,800ft

    Photo: NCH

Avalanche Discussion

On Thursday, we saw a mix of sun and clouds (more clouds closer to the border), a northerly breeze, and a cool-ish day with upper elevation temperatures below freezing. This was followed by light snowfall that fell Tuesday night, with an inch to several inches in the western part of the zone. Overnight temperatures have fallen below freezing for several days, including lower elevations, helping to bring about an end to what had been a very active wet snow avalanche period.  Professionals in the area midweek have reported a collection of small avalanches, dry and wet loose, and shallow pockets of wind slab on Thursday.  

On Sunday 3/2, NWAC Forecasters visited the site of the avalanche fatality near Harts Pass that occurred on 2/28. You can see the initial observation, and a report will be issued in the next few weeks. In addition to this avalanche, forecasters found widespread persistent slab, wet loose, and wet slab avalanches in size up to at least D3. They encountered a natural wet avalanche that ran that day and experienced collapsing and shooting cracks.

While the January Drought Layer has been in our snowpack for over a month, it wasn’t until the late February blustery storm followed by several days of warm temperatures combined forces to “wake it up.”  The culprit? Weak facets buried 2–3 ft (70-100cm) below the surface in the Harts Pass area, and ~4' deep for areas further west.  While persistent slab avalanches have been the focus since the late February storm, the warm weather that followed into the first days of March also brought down impressive wet avalanches, some up to size D3 (very large). Natural wet slides occurred as recently as Sunday near Harts Pass, including one that broke trees and gouged to the ground (SW, 4500ft). 

You can help us gather more data by submitting an observation HERE or via the Avy App. 

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