Bollettino valanghe

West Slopes South

Northwest Avalanche Center
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Pericolo valanghe

Tue
Alta quota
2 · Moderato
Limite del bosco
1 · Debole
Sotto il limite
1 · Debole
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In sintesi

Mostly cloudy skies, easterly winds, and cool temperatures should help limit the avalanche danger on Monday to lingering firm wind-loaded pockets. Steer around smooth pillow-like drifts below cornices, along the base of cliffs, and in chutes.

Problemi valanghivi

  • Wind Slabs

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

    Westerly winds this past week formed firm wind slabs not only along ridges but also cross-loaded mid-slope features. While these slabs are a few days old and becoming harder to trigger, a few recent natural avalanches at Paradise and Crystal are keeping this problem on our minds. Hard slabs like these are very difficult to assess and manage. They tend to fail once you’ve already committed to the slope and break above you. Unless you’re certain, the best thing to do is give them a wide berth. Look for smooth firm pillow-like slabs below steep cornices, near the base of cliffs, and in rock-walled gullies.

    Strengthening easterly winds could start to blow the snow around again on Monday. While they may form a few fresh shallow drifts, this new batch of wind slabs should remain relatively small and harmless. Don’t let them catch you off guard in higher consequence terrain.

    (1/1/2023) Cross-loaded mid-slope features like this can suprise travelers with wind slab avalanches. Photo: Dallas Glass

Avalanche Discussion

On Monday the weather should help the snowpack strengthen and bring generally safe conditions to the mountains outside of those lingering wind-loaded areas. However, the difference between safety and hazard can be very thin when we’re talking about a forecast. If more sunshine occurs or if the east winds blow more snow than we expect, you could see the avalanche danger building in those locations. Pay attention to the weather and compare it to what you expect to happen. If you see clearer skies or more significant blowing snow anticipate loose wet avalanches or more widespread wind slabs. 

Clear skies on New Year's Day allowed us to see several recent avalanches in the Paradise area. A large natural wind slab occurred on an E aspect near Panorama Pt, likely from a cornice fall. The second was a series of smaller wet slab avalanches triggered by loose wet slides in the Edith Creek areas. Other avalanches were seen from the past several days in the above treeline area of the Wilson Glacier. 

Snow on steep southerly slopes became moist mid-day across the zone. While the natural avalanche activity was limited, this formed a new surface crust in this terrain. Fortunately, on slopes that didn’t receive direct sunshine, cold dry soft snow continues to hold tight. 

The upper snowpack generally consists of 15-30in (35-75cm) of settled powder well bonded to the Christmas Crust. While inter-storm layers have been observed, they have not produced any known recent avalanches.

Regioni coperte