Bollettino valanghe

Stevens 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 4 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

You can trigger avalanches in the recent snow that fell over the weekend. Use caution on slopes 35 degrees and steeper in both wind-exposed and sheltered terrain.  Expect another big jump in avalanche danger on Tuesday night as the next storm approaches.

Problemi valanghivi

  • Wind Slabs

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

    You can avoid these avalanches by sticking to wind-sheltered terrain, slopes under 35 degrees, and steering around drifts and thick wind features. These avalanches could be big enough to bury or kill you. You can trigger them immediately on the leeward sides of ridges in stiffer slabs and pillows of snow. Warning signs include cracks shooting through the snow and areas of stiff, wind-sculpted snow. 

    Almost 2 feet of snow that fell Sunday into Monday was transported by moderate westerly winds. Wind slabs may be localized to ridges, but they could be large. The cold air temperatures may keep instabilities from gaining strength. Winds slabs will be the most dangerous of today's avalanche flavors. It's best to avoid the areas where you could trigger them.

     

    (11/27/2022)

    Cracking of wind-stiffened slabs near Stevens Pass Mountain Resort.

    Photo: Joe Dellaporta

  • Loose Dry

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

    Loose avalanches will be easy to trigger on wind-sheltered slopes 35 degrees and steeper. Stay alert in steep terrain. While these small avalanches may be easy to predict, they could push you into a dangerous area if you're not paying attention. You could be injured by hitting shallowly buried logs or other obstacles. If you don't have experience managing loose dry avalanches, it's best to avoid steep terrain. 

    (11/20/2020) Small loose dry avalanches from a previous season. Photo: Matt Primomo

Avalanche Discussion

Prepare for cold temperatures on Tuesday. Bring extra layers and monitor exposed skin for cold injuries. Cold, calm conditions could also form a weak interface for the next storm. 

The snowpack at Stevens Pass elevation has nearly doubled over the weekend. On Monday, observers reported that the 20" of snow that fell since Saturday was very light, dry, and right-side up (soft over stiffer snow). They easily triggered loose avalanches on steep slopes.  Observers on Sunday found that the 12" of snow had widespread wind effects with firm and reactive drifts near treeline terrain. Additional heavy snow arrived Sunday night.

You may find select areas of weaker snow buried in November, especially on shaded, northerly terrain or in the eastern portion of the zone.  In general, observers haven't found the layer near the top of Stevens Pass. Pay attention for whumphing collapses or sugary snow layers like what was found in this observation near Lichtenberg Mtn. If you find signs of instability or propagating snowpack tests, stay off of slopes steeper than 35 degrees.

Despite this last storm,  it's still early season, and the snowpack is shallow. Lots of early-season hazards exist such as shallowly buried trees, rocks, and other obstacles. We're still gathering information about snow and avalanche conditions. Let us know what you see by submitting an observation.

 

Regioni coperte