Bollettino valanghe

Stevens Pass

Northwest Avalanche Center
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Pericolo valanghe

Mon
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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In sintesi

Another round of fresh snow and moderate winds will maintain the possibility of triggering avalanches in wind-drifted snow.  We expect most avalanches to be small, but they could still be consequential if exposed rocks, trees, or cliffs are below you. Sheltered or scoured slopes are safer options, or you can steer around steep terrain with deep drifts. 

Problemi valanghivi

  • Wind Slabs

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

    Winds will shift more westerly overnight on Saturday. While this storm track is more favorable for the Cascade Passes, it won't bring us more than 4-5 inches of snow. Winds will also begin to taper by late morning on Sunday. Still, you can expect another round of small, fresh wind slabs on lee aspects, particularly on sharp ridgelines at upper elevations. Look for deep, stiff drifts below corniced ridgelines or textured surfaces to identify wind-loaded terrain. Small inconsequential test slopes are a great way to check how wind-drifted snow reacts to a load. If you see shooting cracks or trigger a tiny slab, avalanches are more likely, and you should avoid stepping out onto larger steep slopes. We expect these avalanches to be small but could have high consequences depending on the terrain and the number of exposed obstacles beneath you. Steering around steep wind-loaded slopes or choosing sheltered terrain is the best way to avoid any avalanche concerns. 

    (3/20/2022)

    An example of a small wind slab avalanche, like the ones you may be able to trigger on Saturday.

    Photo: Ryan Minton

Avalanche Discussion

The winds didn't turn out to be very impressive on Saturday, and the 4-5 inches of snow that fell across the zone probably only drifted into slabs at upper elevations near exposed ridgelines. However, another 4-5 inches of snow is possible on Saturday night, along with winds from the west. This will likely form new wind slabs in new locations. We'll likely see a short break in weather before the next storm rolls in late Sunday, resulting in the potential for clear skies in the afternoon. The sun isn't very strong this close to the winter solstice, but you might see rollerballs, pinwheels, or small, wet loose avalanches off of rocks and trees warming in the sun. 

Observers in the Stevens Pass area reported soft, dry snow on northern aspects and breakable crusts on southern slopes on Friday. Travel on southern slopes was worse, with thicker crusts at upper elevations due to the recent warm inversion temperatures. They noted calm winds, a lack of recent avalanches, or any signs of instability. 

Over the weekend, a storm brought rain, cooling temperatures, and snow to the zone. A crust formed (12/7 crust) and is buried beneath 2-4 feet of snow. We've found a good bond between the crust and the recent snow in many areas. However, there are reports of weak facets above this crust, possibly a concern for future loading events. Sheltered northern slopes harbor weak surfaces and surface hoar. These weak surfaces could have been buried and preserved under the recent snow. You can expect challenging, low-snow cover travel below 4000 feet and crusts to be unpleasant in the southern aspects. Northern slopes above 4000ft likely provide the best soft snow surfaces for winter recreation. 

If you get out in the backcountry, please consider SUBMITTING AN OBSERVATION and help shape the avalanche forecast. 

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