Bollettino valanghe

East Slopes North

Northwest Avalanche Center
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Pericolo valanghe

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

You could trigger large avalanches at upper elevations, where winds drift another round of fresh snow into thick slabs. Avoid steep wind-affected terrain near ridgelines and confined alpine features. Smaller avalanches are also possible in sheltered terrain. Consider making conservative terrain decisions to avoid getting caught off guard during these small but consistent storms. 

Problemi valanghivi

  • Wind Slabs

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

    Strong winds drifting snow onto slick crusts will likely create reactive wind slabs at upper elevations. To identify wind-loaded slopes, look for actively blowing snow, cornice formations, and pillowlike drifts. Avoid steep ridgeline terrain, confined alpine features, and steep gullies, all likely spots for wind slabs to form. Rain to upper elevations formed a melt-freeze crust on the surface (Solstice Crust), which was recently buried by a few inches of snow. Avalanches could run farther and be larger than you expect on this slick bed surface. 

    There may be lingering storm slabs in sheltered terrain at lower elevations. These avalanches will likely be small, but even small avalanches could push you into obstacles or cause injuries that ruin your season. 

    (12/22/2023)

    Fresh drifts with cracking in steep ridgeline terrain.  

    Photo: Willie Webster

Avalanche Discussion

Another evening, another storm. While Sunday's storm didn't provide quite the snow totals we were looking for, Monday will provide another opportunity for 4-5 inches of fresh snow.  Although East North will escape the highest wind speeds, they will be strong enough to drift the new snow around. Precipitation and winds will likely taper in the morning, so expect the highest avalanche hazard during the first part of the day. 

With only around 8 inches of recent snow over the Solstice Crust, we are still uncertain how this interface will react to a larger snow load. The warmer overall temperatures could help form a favorable bond with this crust, or the few inches of snow could have weakened with cold overnight temperatures, creating sensitive avalanche conditions. 

Near Blackpine Lake on Thursday, observers reported small avalanches failing on a layer of buried surface hoar. The distribution of this problem is uncertain, and observations indicate that this is not a problem in the Highway 20 corridor or the Hart's Pass area. However, these avalanches are evidence that the eastern portion of the zone may hold a more complex snowpack with avalanche concerns that could linger for an extended period of time. Pay attention to red flag signs of instability, such as whumping collapses, and consider digging down to identify the telltale grey line in the snowpack that clearly distinguishes surface hoar layers. 

You can contribute to the avalanche forecast. Please let us know what you see in the mountains by submitting an observation. 

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