Bulletin d’avalanche

Stevens Pass

Northwest Avalanche Center
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Danger d’avalanche

Tue
Alpin
1 · Faible
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
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Périmé — ce bulletin a expiré last year. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

The risk of wet avalanches lingers until we get a solid overnight refreeze at lower and middle elevations. Until this occurs, don't linger under steep overhead terrain where sagging cornices, chunks of snow, or even glide avalanches could naturally fall down.  Sinking into wet, gloppy snow will be a good indicator that the danger is not yet low.

Problèmes avalancheux

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely
    Taille
    1–2

    Wet avalanche activity remains a concern on slopes that don’t see a solid overnight refreeze. If the surface crust is unsupportable, the danger is not yet low. Fresh rollerballs or recent avalanches suggest an increase in wet avalanche activity. While avalanche activity should become more isolated relative to recent days, any avalanches that do occur could be large, potentially involve cornice falls, glide avalanches (on underlying bedrock slopes), or other more destructive wet avalanche types.

     

    (3/1/2025)

    The potential for cornice fall overlaps with other wet avalanche problems as indicated by the rollerballs on the slopes below.

    Photo: Nate Hough-Snee

Avalanche Discussion

Upper elevations, exposed ridgelines, and areas that get clearing Sunday night are more likely to have a firm and more supportable crust, low danger, and better riding quality. Conditions in areas without a firm crust will be very similar to the warm, wet, cloudy, and unpleasant conditions that observers experienced on Sunday. Moist snow or crusts now exist on all but the highest elevation north-facing slopes. With a bit more wind and cooling, Monday should be less hazardous overall, and wet problems may be mostly behind us by Tuesday. The 12/24 interface is gaining strength as the warm temperatures continue to impact it.

On Saturday, a variety of wet avalanche flavors were on display in the eastern portions of the zone. You can read these reports from Rock-Howard-Mastiff and the Chiwaukum Mtns got great views of widespread avalanches from the past week on the eastern edge of the zone. On the 28th, Observers reported large wet loose avalanches near Lake Valhalla and in the Fluer de Lis area in the sidecountry adjacent to Stevens Pass Ski Area.

From Feb. 21-25th, the Stevens Pass zone received over 5 inches of water, 1.5 inches of which was snow above 4000ft on Tuesday. There is now about 2 feet of snow over the 2/24 melt-freeze crust. 

On the 26th, an NWAC forecaster near Stevens Pass got the first post-storm look at upper elevation terrain and observed very large crowns from a reactive 12/24 interface and cornice failures above 6000ft on Rock Mountain and Nason Ridge. They also reported a widespread wet loose avalanche cycle during the day. 

Older observations highlight the widespread wet avalanche cycle that began on Saturday during the atmospheric river. We suspect the rain/snow line over the weekend hovered between 5000 and 6000ft. Many large and very large wet avalanches were reported along the HWY 2 corridor and outside of the Stevens Pass Ski Area.  We are still cataloging this avalanche cycle, so let us know what you see by submitting an observation!

Régions couvertes