Bollettino valanghe

Snoqualmie Pass

Northwest Avalanche Center
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Pericolo valanghe

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

A return to wintery weather will start to build new slabs in wind-loaded terrain. It could take most of the day to receive enough snow to create a real hazard. Use caution around piles of new snow on the lee sides of ridges.

Problemi valanghivi

  • Wind Slabs

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

    As snow starts to accumulate and winds increase, you should see wind-loaded pockets form on the lee sides of ridges. While these small thin slabs won’t pose much hazard at first, they could grow a bit larger by the end of the day. Frequently, we tell you to look for pillow-like slabs and go around. However, poor visibility in the afternoon could make it hard to spot these wind-affected areas. Blowing snow will be your best way to anticipate loaded slopes. Even though these slides should stay relatively small, they could trigger easily over underlying crusts. Don’t let them surprise you and push you off a cliff or down a chute.

    (2/18/2023)

    Signs of wind loading to look for Saturday.

    Photo: Dallas Glass

  • Glide Cracks

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely
    Dimensione
    2–3

    Sure it will start to look like winter Thursday, but Glide avalanche concerns don’t turn-off like a switch. Warm temperatures and sunshine from the past few days have sent water deep into the snowpack, and it will take a bit for it to drain or freeze. Glide avalanches have released days after snowy weather returned to the mountains. Make sure you choose locations to stop and regroup that are away from overhead hazards, especially crevasse-like glide cracks.

    (3/21/2023)

    A natural glide avalanche was observed on Tuesday 3/21 on the E side of Granite Mt. Additional glide cracks can be seen on the adjacent slopes.  Approx: E, 4600ft, (WS-N-D2-R2-G).

    Photo: Alpental Patrol

Avalanche Discussion

Thursday will be a bit of a transition day as we move from spring back to winter. A decent overnight freeze should help “lock up" the surface. This will limit avalanche concerns in the morning. As the storm intensifies later in the day, expect the danger to rise quickly. 

At lower elevations, rain and warm temperatures could keep the snowpack a little wet and unstable. As a result, you may be able to push small loose wet avalanches in very steep terrain. These types of slides will probably only be an issue if they carry you into an open creek or over a cliff. 

It’s March, what forecast would be complete without a mention of sunshine? There’s a bit of a mid-day break in the storm. This could include the sun poking through the clouds. If this happens you may see piles of rollerballs and a few small loose wet slides from the new snow. 

At the moment we expect most avalanche activity to be in the new snow. A firm crust formed on E-S-W aspects and around the dial at lower elevations. In shade areas, cold dry snow remains. Below the surface, the snowpack is generally strong and well bonded. We currently don't have any deeper layers of concern. 

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