Bollettino valanghe

West Slopes Central

Northwest Avalanche Center
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Pericolo valanghe

Wed
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2 · Moderato
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2 · Moderato
Sotto il limite
1 · Debole
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In sintesi

Your largest concern is wind drifted snow which could avalanche with a human trigger along ridgelines, on steep rollovers and around features. Feel for heavier snow, scan for pillows or wind-shaped features, and pay attention to clues like cracking as indicators for steep slopes to avoid. Loose snow could run as small dry avalanches on steep north-facing slopes, and if the sun shines enough there may be wet loose avalanche activity on steep southerly slopes. 

Problemi valanghivi

  • Wind Slabs

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

    Avalanches in wind-exposed areas near and above treeline could occur with a human trigger. On Monday, a few observations with small natural and human triggered wind slab avalanches came in from the West North zone. Snoqualmie Pass zone has seen several human triggered slab avalanches in the last few days as well. Avalanches are mainly expected to be small, and around a foot deep, but there's a chance you could trigger a larger pocket, running a little deeper. 

    You're most likely to encounter reactive wind slabs near ridgelines, in gullies, around rocky outcroppings or on steep rollovers. Some wind slabs may be hidden under a few inches of non-wind-affected snow, making them difficult to find. If you feel thicker snow,  experience long, shooting cracks or other signs of instability, take this as an obvious clue that avalanches could occur on nearby steep slopes. Avoid slopes greater than 35° where you identify wind-loading or other red flags. 

    With warming temperatures there's a chance that previously low-density snow could "slab up" and get heavier, and avalanches more akin to storm slabs could occur if this happens. 

    (4/2/2023)

    A widely breaking avalanche on a convex slope that was human-triggered on Monday in the Snoqualmie Pass zone. The skier was caught, carried, and partially buried.

    Photo: Public Observation

Avalanche Discussion

You can expect to continue seeing loose dry avalanches on Tuesday, although they'll mainly be small. They may be more limited to northerly terrain, and slopes may need to be a little steeper for these sluffs to run, closer to and above 40°. This type of avalanche shouldn't catch you by surprise; they're something that you should expect to trigger if you enter steep terrain.  Make sure to be aware of your and your partners' sluffs if you're getting out on steep slopes. 

Enough sunlight could result in moist snow on steep southerly slopes ,and wet loose avalanches may occur.  Below treeline, very small slab avalanches or loose snow avalanches may still occur, but they're not expected to be large enough to affect your day. Make sure to stay alert for large tree bombs, creek holes, firm snow,  slushy snow, and other springtime hazards at lower elevations.  

Most of our snow came in over the weekend, with  around 1.5-2ft, but we've still been getting a surprise few inches here and there from these early April squalls. In general, we've seen good bonding to the underlying crust which is present on the southerly half of the compass. On the northern half, underlying surfaces are mainly wind-affected, or possibly just a little harder than the fluffy snow we've gotten in the last few days. 

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