Avalanche forecast

East Slopes North

Northwest Avalanche Center
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Avalanche danger

Wed
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
1 · Low
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Highlights

Wet avalanches will be likely as you climb above the cold valley inversion into the warmth and sunshine at upper elevations. They may run naturally when steep rocks and cliffs shed snow, or you could trigger them from your equipment on steep slopes. Rollerballs and wet, heavy snow are signs you should move to lower angle or shady terrain. 

Avalanche problems

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2

    Many areas throughout the East Central zone have already experienced a warm-up, but temperatures above the inversion will notch up again on Tuesday. Natural and triggered wet loose avalanches will become likely as surface crusts break down on southern aspects, and dry snow on western aspects becomes wet and heavy in the afternoon sun. These avalanches tend to initiate from your equipment as you travel or from rocks, cliffs, and trees shedding snow onto steep slopes below. Move out from under these overhead hazards if you begin to see rollerballs or the snow feels wet and heavy. If you're traveling on slopes where you begin to sink deeply into wet snow, move to shadier slopes or stick to lower-angle terrain choices. 

    Our snowpack has a few crusts and persistent weak layers, which can lead to more unusual avalanches and rapidly changing conditions as temperatures warm. You might begin to see slab avalanches failing on these weak layers. Watch for signs of instability and use quick hand pit tests and steep, small test slopes to see how the snow reacts. The snowpack is rapidly changing with warming, so consider choosing simpler terrain with low-angle options and little exposure to overhead hazards. 

    (3/17/2024)

    Wet loose avalanches initiating from steep, rocky terrain. 

    Photo: Willie Webster

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    You could still find isolated areas where you could trigger a wind slab. Look for drifts, textured surfaces, and stiffer snow over softer snow to identify wind-loaded terrain. Ridgelines, the base of cliffs, and large open slopes in alpine bowls are likely places to trigger a wind slab. With a layer of weak faceted snow and surface hoar in the snowpack, the potential for an avalanche to break wider and be larger than expected exists. Shooting cracks, collapsing, and recent avalanches are all signs to choose lower-angle routes. Quick hand pits and test slopes are also a great way to test how the snow reacts before committing to larger, steeper, or more complex terrain. 

    (1/3/2025)

    Shooting cracks in wind drifted snow on Delancy Ridge on a southwest aspect at 6600ft.

    Photo: Katie Warren

Avalanche Discussion

Upper and lower elevations will experience significantly different weather on Tuesday. Cold temperatures in the valley will likely limit many avalanche concerns, while upper elevations might feel more like a warm spring day. As you climb into the warmth at upper elevations, expect to transition from dry snow to wet snow problems, particularly on sunny slopes. We expect surface crusts to break down on southern aspects with the warm temperatures.  Pay attention to whether the snow surfaces are wet or dry to determine if wet avalanches or storm and wind slabs should be your primary concern. 

Sunny weather on Sunday and Monday formed surface crusts on southern aspects, and observers reported rollerballs and small, wet loose avalanches in steep terrain. Last week, soft, dry snow was the norm, with isolated pockets of small wind slabs near ridgelines. One unusual avalanche on Poster Peak stepped down into older, deeper snow layers. While this avalanche occurred in very steep, unsupported terrain and may have been triggered by a cornice fall, it's enough to keep uncertainty about these older layers in our forecast. 

Friday brought 6-8 inches of snow to the area with moderate winds, and this quickly formed touchy wind slabs along ridgelines that were especially easy to trigger where they formed over weak snow on a sun crust from New Year's. This storm also buried a widespread surface hoar layer throughout the area. Other professional observers and I found this surface-hoar layer reactive in snowpack tests. A thin melt-freeze crust associated with weak grains buried between 1.5 and 2 feet deep have also produced unstable test results. These are all layers to watch out for as warming temperatures change our snowpack rapidly. 

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