Bollettino valanghe

Stevens Pass

Northwest Avalanche Center
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Pericolo valanghe

Mon
Alta quota
3 · Marcato
Limite del bosco
2 · Moderato
Sotto il limite
2 · Moderato
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In sintesi

The storm is tapering off, but you could still trigger avalanches where winds formed deep drifts of snow. Steer around steep slopes below ridgelines and alpine bowls with stiff wind drifted snow. Daytime warming and a slight chance of sun breaks could make wet avalanches possible at lower elevations. 

Problemi valanghivi

  • Loose Wet

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

    If the sun breaks through the clouds or the day gets warm enough, wet avalanches will be possible, particularly in the afternoon. This time of year, fresh snow doesn't take long to become wet, heavy, and start to slide. You might be more likely to trigger these avalanches where new snow rests over slick crusts. Move to lower-angle terrain if you begin to see rollerballs or snow shedding off trees and rocks. 

    (12/9/2024)

    An example of a small skier-triggered wet loose avalanche that ran on a slick crust. 

    Photo: Katie Warren

  • Wind Slabs

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

    Recently formed wind slabs may still be reactive, even as snowfall and winds taper off overnight on Saturday. A few inches of fresh snow could hide textured surfaces, so look for cornice formations and pillowlike drifts, or feel for stiffer surface snow layers to identify wind-affected terrain. Cracks shooting out from your equipment or recent avalanches are signs to move to lower angle or wind-sheltered slopes. You can also use small wind-affected test slopes to see how the snow reacts. Snow that fractures and slides easily means avalanches are more likely. Smaller storm slabs or loose snow avalanches are possible in sheltered terrain.

    The stormy weather has prevented direct observations from the upper elevations, but we expect wind slabs to be larger and more reactive as you ascend in elevation. 

    (3/15/2025)

    A small skier triggered wind slab on a north aspect near Lake Valhalla. 

    SS-AS-R1-D1, 5500ft, N aspect

    Photo: Jeremy

Avalanche Discussion

Wind and snowfall will taper off overnight on Saturday. A few showers may linger into Sunday, and since it's spring, the weather may be convective, with short bursts of precipitation followed by brief sun breaks. 

Over the past few days, NWAC forecasters and other observers reported reactive wind slabs, particularly along ridgelines at mid-elevations. We expect these to be gaining strength, but you could certainly still trigger an avalanche in wind-loaded terrain. 

The snowpack underwent a major transition since the atmospheric river (AR) storm of February 21-25th. This AR crust is now buried 2-3ft deep and at elevations up to approximately 6000ft, the upper snowpack has a few thin melt-freeze crusts from warm temperatures in early March. On Thursday, I found a few storm interfaces buried 6-10 inches deep that showed signs of instability in snowpack tests. We expect these layers are gaining strength, but with this next storm moving in so quickly, we can't rule out avalanches into Thursday's snow layers. South facing terrain may have a thin surface crust, from a briefly sunny morning on Friday. 

On high elevation, northerly aspects, there's a chance that you could find buried surface hoar, 2-3 feet below the surface. On the 10th, observers in the Foss River drainage reported triggering isolated avalanches, which are suspiciously indicative of this weak layer.

If you make it into the backcountry, please share with us what you find by submitting an observation HERE or on the Avy app. 

Regioni coperte