Bollettino valanghe

Snoqualmie Pass

Northwest Avalanche Center
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Pericolo valanghe

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

Snow, strong winds, and recent rain will create dangerous avalanche conditions on Tuesday. Dry slabs will be more likely as you increase your elevation, especially on wind-loaded slopes, while wet avalanches remain possible at all elevations. With multiple overlapping hazards and high uncertainty, consider avoiding steep, open terrain during the storm.

Problemi valanghivi

  • Storm Slabs

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

    While the new snow may bond well to the wet surface below, instabilities within the storm snow are a concern Tuesday—especially on steep, unsupported slopes above 5000ft. Feel for hard over soft snow, look for shooting cracks and recent avalanches, and avoid steep slopes nearby if you see any of these signs. You can also use small test slopes and hand pits to check slab behavior. The greatest danger will be on exposed mid and upper-elevation slopes where moderate to strong winds build thick drifts below ridgelines, cliff bands, and along gully tops and sides. In these areas, wind slabs could break up to a few feet deep and easily bury or injure a traveler. Look for blowing snow and textured surfaces, and avoid steep slopes loaded with wind-affected snow.

    (12/16/2024)

    A human-triggered slab avalanche from earlier this season. Expect more reactive and consequential avalanches on wind-loaded and confined terrain features as you ascend in elevation on Tuesday.

  • Glide Cracks

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    2–2.5

    We are using glide avalanches a catch-all for the gamut of wet avalanche types you could find on Tuesday.

    You’ll be most likely to encounter small wet loose avalanches between 4000–5000 ft, especially where rain falls on fresh snow. Most will be small, but even a small slide could knock you off your feet in steep or exposed terrain. Higher up, things get trickier. It may look like winter above 4500ft, but a week of warmth followed by a rainstorm has pushed a lot of water into the snowpack. We suspect the March AR Crust has likely broken down and that water is making its way to points below. Thus, while wet slab avalanches within the snow above the March AR should have already occurred, the chance for a deeper release persists. Even if the spigot is off on Tuesday, the damage may already be done—and we don’t yet know how the snowpack will respond. Glide and wet slab avalanches, gouging wet loose slides, cornice falls, and chunks of snow breaking off rocky ledges all remain possible. These are hard to predict, so the safest option is to steer clear. Don’t linger beneath glide cracks, sagging cornices, or snow-loaded cliffs, and avoid being on or under large avalanche paths while the snowpack continues its messy transition into spring. 

    (4/4/2025) 

    Lots of snow still clings to rocks and cliffs. Shed/glide/cornice avalanches are all a concern. Don't linger below overhead hazards such as glide cracks and cornices.

    Photo: Ian S

Avalanche Discussion

About 3/4 of an inch of water fell between Sunday night and Monday, mostly as rain up to the ridge crest. Temperatures and snow levels are now trending down and will continue to fall overnight into Tuesday, as the next system delivers another round of snow, rain, and wind.

Uncertainty is very high right now. The snowpack is being hit with continued precipitation, wind, and fluctuating rain/snow lines, while backcountry observations are becoming scarce. Dry and wet avalanche problems are overlapping on many slopes, making even normally manageable new snow issues harder to predict and navigate. The snowpack is slowly transitioning to spring—but it's not quite there yet.

On the bright side, limited snow settlement after the recent rain suggests the snowpack may be draining well, and some older weak interfaces may have made the transition to more benign melt forms. Still, we can’t confidently rule out deeper wet instabilities just yet. With so much weak, wet snow in the mix, any slide that starts has the potential to gouge deep and pick up a lot of mass.

All of this points to one thing: give complex and consequential terrain a wide berth on Tuesday, even if you’re not seeing obvious red flags. In addition, be cautious when traveling through the lower elevation band as thin cover, open creeks, rocks, and trees are all creating dangerous travel hazards. 

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