Bollettino valanghe

West Slopes South

Northwest Avalanche Center
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Pericolo valanghe

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

In sintesi

You may find a few small wind drifted slabs at higher elevations and in exposed terrain. While many might not move, others could pop with little effort. Be leery of pillow-like drifts on high consequence slopes.

Problemi valanghivi

  • Wind Slabs

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

    Strong and gusty winds redistributed the new snow in exposed areas likely building slabs in weird places and leaving a rather erratic loading pattern. These new wind slabs formed on a variety of surfaces including firm crusts, wet snow, and possibly dry weak snow. This will make predicting how any one slope may react quite tricky. 

    Look for clues such as scoured slopes, textured surfaces, and drifts to point toward wind loaded slopes. You may also feel the change in depth and firmness of the new snow. Once you’ve anticipated which slopes might hold pillow-like wind slabs, turn your attention to likely trigger points. Rocky slopes, convex rollovers, and complex terrain should all be suspect. 

    Even if these slides are relatively small, don’t let one knock you off your feet and take you for a nasty ride.

    (3/10/2025)

    Quick signs of highlighting local wind patterns in an exposed opening. 

    Photo: Dallas Glass

Avalanche Discussion

Sunday night’s storm was pretty meager, but it did bring a fresh coat of paint to the mountains and greatly improved travel conditions. Most weather stations reported 3-6 inches of new snow at mid-elevations. Wind speeds were impressive (20-30mph gusting 40-50mph) throughout the storm. On southerly aspects, this new snow fell on a stout and often slick crust. Wet snow, facets, surface hoar, and thin breakable crust were all reported on northerly slopes prior to the snow. This new interface (3/9) is worth watching moving forward. 

Sunshine Monday morning, likely warmed the surface on southerly slopes. Any wet snow should freeze overnight and form a weak crust. Tuesday looks cloudy, but if the sun does come out, it will need to breakdown this firm surface before wet avalanches become much of a concern. Similarly, a bump in temperatures in the afternoon could make wet loose avalanches more likely, but it will need to get through the crust first. 

Generally, avalanche concerns are limited to the snow above the robust atmospheric river (AR) crust. On sunny aspects, that’s just the new snow. In north facing terrain, there may be a few more layers before you hit the “new ground.” Even though all these layers are shallow, with a firm crust like this below, slides could run easily down the slope. 

Regioni coperte