Bollettino valanghe

West Slopes South

Northwest Avalanche Center
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Pericolo valanghe

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

In sintesi

Before you commit to larger or more consequential slopes, take a good hard look for any signs of wind-affected snow. If you see drifts, wind lips, or pillow-like slabs, then seek out an alternate less wind-loaded or lower angled route.

Problemi valanghivi

  • Wind Slabs

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

    We received a few reports of natural and human-triggered wind slabs on Sunday in the West South zone. These wind-loaded areas formed on Saturday during a strong E-S wind event. That means they are still relatively fresh and could exist in some unusual spots. Pay close attention near convex rollovers, along the base of cliffs, in the tops of chutes, and on the sides of mid-slope gullies.

    Unfortunately, a few inches of soft snow, could make spotting these wind slabs a bit tricky. So, let the recent avalanche activity be your most compelling piece of information.  Anticipate wind slabs on exposed mid and upper elevation slopes, until you can confidently rule them out. Steer around firmer pillow-like slabs, especially in large and higher consequence terrain.

    (3/5/2023)

    A human triggered wind slab near 3-Way Peak in the Crystal Backcountry. N, 6500ft, 

Avalanche Discussion

The avalanche danger is slowly dropping across the zone as we get a bit further from the storm (3/1-3/4) and the E-S wind event (3/4). The clear winner over the past few days was Mt St Helens, where several feet of snow fell. Given the significantly higher storm totals and strong winds, you may encounter locally more dangerous conditions in this area. 

This past week’s cold temperatures and near-constant snowfall resulted in deep travel conditions! Outside of wind-affected areas, the upper snowpack is largely right-side-up over the 2/25 interface. Not surprisingly, avalanche activity has been limited to a few small natural and human-triggered wind slabs and loose dry avalanches. The most recent of these slides were a handful of wind slabs in the Crystal Mt backcountry on 3/5 (N, ~6500ft). Mostly clear skies on Sunday also formed a new crust on steep sunny aspects. 

The biggest question for Monday will be the sky and any potential for loose wet avalanches. We think increasing clouds and new curst will limit any wet issues. However, prolonged periods of warm sunshine could result in snow shedding from rocks/trees and causing small point release avalanches. If you see new rollerballs or small slides, expect more natural avalanches from similar terrain.

Regioni coperte