Bollettino valanghe

Stevens Pass

Northwest Avalanche Center
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Pericolo valanghe

Thu
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
2 · Moderato
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In sintesi

While there still may be isolated pockets of unstable wind-drifted snow to catch you off guard, wet avalanches will be the most common problem you encounter on Wednesday. As steep, sunny slopes warm up and the snow becomes wet and heavy, move to shady terrain and watch for chunks of snow shedding off steep rocks above. 

Problemi valanghivi

  • Loose Wet

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

    We've slowly turned the thermostat up over the past few days, along with decreasing cloud cover. Wednesday might be the warmest and sunniest day yet, so wet avalanches on steep terrain in the sun will be increasingly likely as the afternoon progresses. Surface crusts formed on Tuesday must break down before this problem becomes widespread, but with a mild night and 5000ft temperatures in the 40°F's, this probably won't take long. Steep rocks or cliffs could also shed heavy chunks of snow from above, so don't pause below these overhead hazards for long. If you begin to see rollerballs, trees, and rocks shedding snow, or the snow becomes sticky and wet, consider moving to shady slopes or dialing down your slope angles. 

    (3/21/2023)

    Wet avalanches often initiate from snow falling from rocks and trees warming in the sun. 

    Photo: Brooke Maushund

  • Wind Slabs

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

    Wind slabs are becoming more difficult to trigger this far out from the storm. However, in isolated areas, there is still a chance of getting surprised by triggering a wind slab that rests over weak snow. The most likely place to get caught in a wind slab is at upper elevations, in very steep unsupported terrain, or confined rocky chutes. This is also the same terrain where a small avalanche could have high consequences, so consider this potential before stepping out into more complex, aggressive terrain. 

    (1/11/2025) Crown of intentionally triggered windslab, NW ridge Tye Peak. Photo: Ryan Minton

Avalanche Discussion

Tuesday was sunnier than anticipated, and small, wet, loose avalanches were reported on steep southern slopes in the Stevens Pass zone. Wednesday's temperatures will notch up again, and we expect clear skies earlier in the day. So we expect increasing potential for wet avalanches as the day progresses. Enjoy this last spring-like day before we trend back towards more seasonably cold temperatures. 

After an active start to the weekend, observers at Stevens Pass reported indicators that the new snow is slowly gaining strength. Reports of avalanches and obvious signs of instability are decreasing, and observers indicate that stability test results indicate that recent weak storm interfaces are becoming more stubborn. An NWAC forecaster near Skyline Lake found numerous resistant and non-propagating test results and couldn't trigger cracking or unstable snow on unsupported convex features. They did find large facets and, to a lesser extent, surface hoar buried in some locations. The most problematic snowpack structure was on steeper, southerly aspects. The recent snow is cohesive and over 4-finger hard in some locations. 

On Saturday, observers triggered numerous avalanches in wind-loaded and sheltered terrain, failing on a weak layer/crust (1/10) interface. Observers in the Skyline Lake, Lichtenberg Mtn, Yodelin, and Lanham Lake areas reported triggered avalanches, propagating test results, or other signs of instability. Below last week's crust, there are no layers of immediate concern. At lower elevations, prepare for challenging travel on breakable crusts and refrozen chunder under the forest canopy. 

Let us know what you see when you're in the mountains by submitting an observation.

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