Bollettino valanghe

Stevens Pass

Northwest Avalanche Center
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Pericolo valanghe

Sun
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

Easterly winds are in store for Stevens Pass again tomorrow, maintaining the possibility of triggering an avalanche in stiff wind drifted snow at mid and upper elevations. Some of these slabs formed over weak snow layers and could surprise you by breaking widely across terrain features. Choose terrain sheltered from the wind and avoid steep slopes with deep drifts. 

Problemi valanghivi

  • Wind Slabs

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

    The easterly wind event continues, and the recent snow drifted into wind slabs that rest over weak, faceted snow in some locations. Look for wind-textured and stiffer snow surfaces to help pinpoint where you could trigger an avalanche. If you see cracks that shoot away from you in deep drifts, steer around steep terrain or move to more sheltered slopes. Likely locations for wind slabs to form are below corniced ridges, convex rolls, steep gullies, and at the base of cliffs. You can use small, inconsequential test slopes to check how easily the snow slides. However, with inconsistent distribution of these weak layers, these tests could be misleading. Rather than assessing your way into steeper terrain, just avoid the problem by sticking to well-supported or lower-angle slopes and seeking wind-sheltered terrain for travel. Slides could be just a few inches deep or break 1.5ft down on the stout crust from Early February (see photo). Any slide that breaks on this crust could be larger and wider than you may anticipate. 

    (2/13/2024)

    Skiers triggered a slab avalanche (D1.5) at upper elevations on 2/13.  Jim Hill, NE, 6,500ft

Avalanche Discussion

High clouds should continue to thicken throughout the day on Saturday. Easterly winds should help keep surfaces cool, but expect some warming further west in the zone, and you could see fluctuating temperatures as warmer air moves into the mountains. This probably won't contribute much to the avalanche hazard, but a few rouge roller balls or snow shedding from trees is possible. This will be more likely if the sun sticks around longer than forecasted.

Before the east winds ramped up on Wednesday, surfaces consisted of surface hoar and faceted grains over brittle to breakable crusts on most aspects. 1-1.5ft down, you can find a thin layer of small sugary facets above the stout crust from early February. On Wednesday, an NWAC forecaster found near surface facets, a layer that may now lurk below recently formed wind slabs. On Tuesday, a skier triggered a slide 1.5ft deep on this crust on a NE aspect at 6,500ft on Jim Hill. A different party on Jim Hill reported some large whumphing collapses that same day. Other observations from this zone and the neighboring East Central and East North zones show this layer to be problematic as well.

If you make it out, please share what you found with an observation.

Regioni coperte