Bollettino valanghe

West Slopes South

Northwest Avalanche Center
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Pericolo valanghe

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

After a cool and cloudy start, expect things to warm up, and the snow might start to fall down. You could trigger an avalanche on steep slopes with more than a few inches of wet, sticky snow. Any shed-style natural avalanches should generally be isolated to very steep and rocky terrain.

Problemi valanghivi

  • Loose Wet

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

    Friday, you’re dealing with two different flavors of wet avalanches. As the snow surface softens, you may push loose slides in steeper terrain. Often, we think about wet, sticky snow deeper than your ankle as the threshold. These slides should be generally small and easier to manage. However, they can carry you over a cliff,  into a creek, or bury you in a gully if you’re not careful. 

    We aren’t expecting a widespread shed-cycle Friday, but you could start to see a few isolated larger natural wet avalanches. Cornice, glide, wet slab, and gouging wet loose slides could all occur. This version of wet slides is very difficult to predict but much more consequential. Look for routes that help limit your exposure to looming cornices or blocks of snow clinging to rocky faces. These things could fall down with little or no warning. If you start to see larger shed-style events, get out of large avalanche terrain.

    (4/10/2024)

    This small wet loose avalanche ran into a gully. This terrain trap could magnify the consequences of the slide, despite it's small size. 

    Photo: Dallas Glass

Avalanche Discussion

Dynamic spring weather on Friday will cause conditions to change quickly. The danger should be the lowest in the morning, while cool temperatures and cloud cover keep the snow surface more frozen. You won’t need blue sky for that to change. A bit of filtered sunshine and warming temperatures will do. If you’re noticing conditions warming up, the snowpack probably is as too. 

Sure, the weather feels like spring, but the snowpack hasn’t fully made the shift. Only lower elevations and steeper sunny slopes have become warm and more uniform. Elsewhere, the snowpack is still layered and relatively dry. Until it fully transitions, we could be in for a few surprises. While not as big or widespread as some years, cornices still overhang many alpine ridgelines. They could sag and fail during this warm weather. You don't want to be on or under them if that happens. 

The upper snowpack consists of recent snow over the Early April Crust. Much more snow fell on the volcanoes than closer to the crest. In some places, it may be 1-1.5ft deep. As a result, you could see larger and more dangerous slides on the bigger mountains. On more shaded aspects above about 6000ft, you can still find dry, settled snow. At this point, any wind slabs are several days old and unreactive. Even still, don’t ignore an obvious pillow-like drift in high-consequence terrain. If you ascend above our forecast area (8000ft), wind slabs could become more common. 

The lower-elevation snowpack is going fast. This is particularly true on southerly aspect. Many melted back to bare ground over the last month. Typically, continuous snow starts around 4500ft in shaded terrain. The lack of snow and faster transition to spring at these elevations helps limit the hazard. Any avalanche activty should be limited to a rouge block of snow sheding from rocks or a large avalanche descending from higher in the terrain. Open creeks, holes, bare ground, and obstacles are common at these lower elevations.

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