Bollettino valanghe

Snoqualmie Pass

Northwest Avalanche Center
Vedi sulla mappa

Pericolo valanghe

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

In sintesi

If you travel in higher elevation or more exposed terrain, you may find a few small pockets of wind loaded snow. They could be a bigger deal on rocky slopes or steep convex rollovers. Some avalanches may trigger easily or run far over a firm crust.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–1.5

    Strong and gusty winds during the recent storm (Sunday night) significantly redistributed the snow in exposed areas. These wind slabs will be greater than 24hrs old and should be starting to heal, but don’t fully right them off just yet. On Monday drifts up to 15” deep were found in the eastern portion of the zone. Some test slopes cracked, others didn’t. 

    A dusting of new snow might hide some of the smaller clues like textured surfaces. Instead, look for wind lips and drifts to point towards loaded slopes. You’ll also probably feel the snow depth change as you travel. Take note of shallow, scoured features and spots with deeper pockets. 

    Once you’ve identified which slopes could hold wind slabs, turn your attention to likely trigger points. Areas beneath cliffs, complex terrain, and very steep slopes are all suspect. Since these new slabs formed over a wide variety of old surfaces each slope might act a bit different than the last.

    (3/10/2025)

    Quick signs of highlighting local wind patterns in an exposed opening. 

    Photo: Dallas Glass

Avalanche Discussion

Sunday night’s storm brought a nice fresh coat of paint to the Pass. Down low there isn’t much new snow (1-3 inches), but once you get above 4500ft, the snow depth starts to increase (4-7 inches). Sure, this is pretty meager by Cascade standards, but it improved travel conditions in open areas, even if most of it didn’t make it through the forest canopy. 

Winds during the storm averaged 20 mph and gusted much higher. Scoured slopes, textured surfaces, firm drifts, and snow blown out of trees were common sights Monday. While the Pass could see some snow flurries or get another inch or so of snow, this won’t add to the hazard. Instead, the danger is slowly dropping as the new snow heals. 

Sunshine on Monday caused the new snow to become wet on southerly aspects. One backcountry skier was caught and carried by a small wet loose slide on Mt Snoqualmie and a small natural wet loose slide was seen near Mt Margaret. Any wet snow will likely form a breakable crust Monday night. If the sun comes out Tuesday, it will need to break down the crust, before wet loose will be an issue. A bump in temperatures, Tuesday afternoon, could make wet loose slides more likely, but like the sun, it will need to get through the surface crust first. 

Avalanche concerns should be limited to the snow above the atmospheric river (AR) crust. On southerlies, that’s just the new snow. On shaded aspects, you might find a shallow layered snowpack that could include thin crusts, facets, or even surface hoar.

Regioni coperte