Bollettino valanghe

Snoqualmie Pass

Northwest Avalanche Center
Vedi sulla mappa

Pericolo valanghe

Thu
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

Another round of snow and wind could build additional slabs along exposed ridges and below cliffs. Even though these potential avalanches should be relativity small, conditions are getting more complex and variable. Be leery of pillow-like drifts, especially in higher consequence terrain.

Problemi valanghivi

  • Wind Slabs

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

    This isn’t a particularly windy storm, but stronger gusts will probably drift snow in more exposed and wind prone areas. As a result, new wind slabs might not be super common, but you may see them in the tops of chutes, in rocky terrain, and at higher elevations. With prevailing winds out of the SE, slabs may form in different locations than normal. Often these less common wind directions catch travelers by surprise, even when conditions aren’t that dangerous. 

    Watch for blowing snow, textured surfaces, and small drifts to indicate local wind patterns and point toward loaded slopes. In addition to the abnormal wind direction, these slabs are forming on a wide variety of surfaces. This could make predicting how any slope will react very challenging. Given all these factors, don’t trust wind loaded pockets, especially with nasty runouts. 

    Older wind slabs from Sunday night should be hard to trigger, but could still occur on unsupported or complex terrain.

    (3/10/2025)

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

    Photo: Dallas Glass

Avalanche Discussion

At face value, this storm doesn’t really stand out. Even this week’s weather pattern isn’t particularly eye-catching. Despite all this, there’s a bit more nuance and uncertainty to the current conditions. 

We’re really only worried about the upper snowpack above the stout and thick atmospheric river (AR)crust. What’s impressive is there’s a lot of variability in that foot or two of snow. You might find slopes scoured down to this icy layer. In others, the snow is much deeper. Layers of recent snow and occasional melt-freeze crust are common. An observation from nearby in the West Central zone also hints at the possibility of buried surface hoar at the 3/9 interface. All this to say, some slopes might slide easily, others may feel “glued in.” 

There’s probably not quite enough new snow for a meaningful storm slab problem in wind sheltered terrain. However, with all this variability take the time to dig hand pits, use up track tests, and jump on small slopes to see how they react before committing to larger terrain. 

At lower elevations, it will probably be raining Wednesday. A bump in temperatures in the afternoon could cause the snow level to climb. We aren’t that worried about rain on snow. However, near the rain-snow line, wet heavy snow may create rollerballs and small wet loose slides, particularly where it’s sitting over a crust. 

One way to look at all this is the AR crust is basically the new ground. The snowpack above is shallow and variable. That makes it harder to predict.

Regioni coperte