Lawinenlagebericht

Snoqualmie Pass

Northwest Avalanche Center
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Lawinengefahr

Tue
Hochgebirge
2 · Mässig
Waldgrenze
2 · Mässig
Unterhalb
2 · Mässig
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Kernpunkte

A quick Sunday night storm will create fresh drifts of snow where you could trigger an avalanche on Monday. Look for textured surfaces and pillowy dunes of snow to identify slopes that may be harboring an unstable wind slab and steer around steep, open, and consequential wind-loaded slopes. If the sun pops, small wet loose avalanches and rollerballs in the fresh snow could initiate quite quickly.

Lawinenprobleme

  • Wind Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1–2

    Most slab avalanches should be small on Monday, however, we wouldn't be surprised to find a large avalanche on an exposed slope at the higher elevations, where a slab could break up to a foot deep. Expect the highest hazard in the morning hours soon after slab formation. Slabs will form on a mixed bag of surfaces, leading some to bond well on a certain slope and poorly on another. Winds tail off significantly overnight, so you probably won't see active wind-loading on Monday. Instead, look for visual clues to identify where slabs may be lurking. Look for recent avalanches, shooting cracks, textured surfaces, and chalky lens-like drifts, and feel for hard over soft, or hollow-sounding snow. Slopes below cornices, convex rollovers, cliff bands, tops of chutes and the sidewalls of gullies are all prime locations. If the higher end of forecasted storm totals pans out, you could also find a small storm slab avalanche outside of the wind zone, especially at the higher elevations.

    You can use hand pits, uptrack tests, and small safe test slopes to help gauge reactivity, but this only helps if the location for your tests is a reasonable facsimile of the slope you are considering. Remember that a small avalanche can carry big consequences if it knocks you down above cliffs or trees, or if it drags you into a gully where the debris stacks up deep. Wind slabs typically need a few days to heal, so the safest bet is to avoid wind-loaded slopes on Monday, especially where the drifts are deeper or the consequences of any fall are severe. 

    (3/5/2025)

    A wind slab in complex, rocky, and consequential terrain. A good location to avoid on Monday.

    Photo: Shane Robinson

  • Loose Wet

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Likely
    Größe
    1

    It won't take long for the intense mid-March sun to cause the fresh storm snow to fall on steep slopes. Whether or not this is a problem will depend on whether the slope you are on, or the one above you, is seeing the sunlight. If it is, expect rollerballs and perhaps some small wet loose avalanches. If the clouds roll back in it will likely stabilize quickly. Just pay attention and if you are on or below a steep slope in the sun, move quickly and head for lower-angle terrain or a shaded slope.

    (3/5/2025)

    Wet avalanche activity due to solar input on 3/5. If the sun pops on Monday, expect the new show to start to shed.

    Photo: Shane Robinson

Avalanche Discussion

Observers at the Pass on Sunday noted a better overnight refreeze than the night before and no obvious signs of instability. Dry snow was still observed on high elevation north-facing slopes and good corn was found on sourtherlies.

With the incoming storm, it's hard to say exactly how much precipitation will fall as water vs. snow, but somewhere around 1/4 rain to 3/4 snow at the middle-elevations seems like a decent bet. How that shakes out will impact reactivity and size of avalanches. That uncertainty stacks atop uncertainty around the current surface conditions. Dry snow, surface hoar/facets, frozen crusts, wet crusts, and wet snow are all on the surface somewhere. Below the surface, the 3/4 crust is between 1-6" down. Any potential avalanches on Monday should be relegated to within the new snow, at the new/old interface, or perhaps a few inches deeper if there is weak snow at the surface. Some could go deeper down to the 3/4, but that is unlikely. We don't expect any activity to occur below the 3/4 crust. 

Stay humble and don't assume that minimal hazard on one slope will translate onto another. Also, stay way back from cornices and don't linger under any open glide cracks. 

There should be fun and safer snow to be found outside of the wind zone!

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