Bollettino valanghe

Snoqualmie Pass

Northwest Avalanche Center
Vedi sulla mappa

Pericolo valanghe

Sat
Alta quota
2 · Moderato
Limite del bosco
1 · Debole
Sotto il limite
1 · Debole
Open full map
Non aggiornato — questo bollettino è scaduto 6 months ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Winds are expected to be strong enough to transport snow onto leeward slopes on Friday, possibly creating shallow slabs. Use visual clues, such as textured surfaces or fresh cornices, to help identify wind-loaded features to avoid. In areas with minimal snow over a crust, you may be able to push loose slides on steep slopes.

Problemi valanghivi

  • Wind Slabs

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

    With plenty of low-density snow in place and an uptick in winds expected on Friday, shallow wind slabs are not out of the question. Look for new pillow-like drifts, textured surfaces, fresh cornices, or scoured areas to help identify where wind slabs could be lurking. The wind often likes to deposit snow on convex rollovers, near the base of cliffs, or in confined chutes/gullies. So approach these features with a keen eye, and if you notice signs of wind-loading, find a new route.

    In more sheltered locations, you could trigger loose dry slides in the low-density snow. Use good travel techniques and don't get caught off guard by a small avalanche in consequential terrain, regardless of whether it is a slab or loose.

    (2/17/2026)

    A very shallow wind slab on Silver Peak. This one was triggered by skiers near a ridgeline containing some rocks.

Avalanche Discussion

Conditions are slowly changing at Snoqualmie Pass. This week's low-density storm snow has incrementally increased by a few inches per day. On Friday, you could find that the 2/7 crust is as much as 1.5-2 feet below the surface in favored locations within the zone.  In addition to the snow starting to pile up, the winds are going to increase as we head toward what should be a windy Saturday. 

We have two layers of concern in the upper snowpack - the 2/13 interface and the 2/7 crust. Both are associated with weak grains such as buried surface hoar or near-surface facets. To date, we haven't had much reactivity on these weak layers since the snow above them has been generally light and fluffy. The question is whether the change in weather will be enough to form the slab needed to activate these layers? Our hunch is that we won't reach that point on Friday.

But you should be aware that these weak layers are lurking beneath the surface. If you see red flag signs of instability, such as shooting cracks, whumpfing collapses, or new avalanches, be prepared to adjust your plans. 

The distribution of these weak layers is primarily determined by exposure to sunshine. On shaded aspects, you can likely find the 2/13 interface if you have a clean pit wall. It will be the thin grey line 4-6 inches above the easily identifiable 2/7 crust. On slopes that often receive direct sunshine, you likely won't find the 2/13 and the 2/7 is much closer to the surface.

Regioni coperte