Bollettino valanghe

Snoqualmie Pass

Northwest Avalanche Center
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Pericolo valanghe

Sat
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
2 · Moderato
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In sintesi

Rain down low and snow up high will create a wide spectrum of conditions and avalanche concerns Friday. Pay attention to the consequences of the terrain. Don’t let one of these smaller slides push you into a creek or over a cliff.

Problemi valanghivi

  • Wind Slabs

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

    While this isn’t a very windy storm, the only place we think you’ll encounter a significant slab is where the new snow manages to drift into slightly firmer and deeper pockets. These small wind slabs will probably be localized to right near ridgecrest and in other exposed spots like the top of chutes. Drifting snow and textured surfaces will probably serve as your best observations to find these wind-loaded areas. Don’t let one of these smaller slides take you for an unexpected ride.

    (1/24/2023) Visual clues of possibly wind loaded slopes. Photo: Dallas Glass

  • Loose Wet

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

    Rain during the day Friday will maintain loose wet avalanches concerns on any steep open slope. If you’re near or below the rain-snow line you may find wet mushy snow, rollerballs, and fan-shaped piles of debris. When you see these clues be leery of nearby terrain greater than 35 degrees. In general, these slides should remain small and easier to manage. However, if one of these avalanches gets moving on a long continuous slope, it could entrain enough snow to grow large and deadly. 

    While we aren’t expecting a widespread loose wet cycle, you could encounter a few natural avalanches. These would be most likely during periods of heavier precipitation or sunshine. Since one of these avalanches could descend onto you from above, don’t linger below steep open areas.

    (2/7/2023)

    Example: Wet Loose activity due to rain from earlier this winter.

    Photo: Jonathan Spitzer

Avalanche Discussion

The southerly flow with this storm system doesn’t really favor Snoqualmie Pass. So, until the winds turn more southwesterly sometime Friday, we aren’t expecting too much precipitation. This should help limit the avalanche danger. 

Thursday was quite warm at Snoqualmie Pass, even at mid-elevations. This follows several days of warmer, often sunny, weather. While we didn’t quite get the precipitation we expected, below treeline the snowpack could be on the move. You may see an isolated glide or shed avalanche. Don’t hang out under slopes with crevasse-like cracks or blocks of snow still clinging to rocky faces. These avalanches can fail with little or no warning. 

Prior to this storm, the upper snowpack consisted of 12-18 inches (30-45cm) of settled snow over the 3/31 crust. Avalanche activity was generally limited to smaller loose wet avalanches on steep rocky slopes. One larger avalanche occurred on the north side of Chair Peak Tuesday. A block of ice seems to have triggered a 2-3 foot deep slab, that formed a narrow channel of debris all the way down to Snow Lake. Odd isolated larger slides like this could continue to occur as the snowpack struggles to transition from winter to spring.

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