Bollettino valanghe

East Slopes South

Northwest Avalanche Center
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Pericolo valanghe

Wed
Alta quota
2 · Moderato
Limite del bosco
1 · Debole
Sotto il limite
1 · Debole
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Non aggiornato — questo bollettino è scaduto 3 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Recent storm snow totals haven't been impressive, but some moderate winds may have formed shallow pockets of wind drifted snow where you could trigger a small avalanche. The most likely places to encounter these stiffer slabs of snow are upper elevations just below ridgelines. Look for textured surfaces or deeper pillows of snow to identify steep, wind-loaded slopes to travel around. 

Problemi valanghivi

  • Wind Slabs

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

    This storm has been slow to impact the east slopes, but precipitation is forecasted to increase overnight. We likely won't get more than 2-4 inches of new snow, but ridgeline winds at upper elevations will be enough to form shallow wind slabs. They could be more prevalent in the HWY 410 corridor and near Bumping Lake, with more recent snow in these areas. Consider steering around steep terrain if you see actively drifting snow or long cracks that shoot away from you. You can also use visual clues like textured surfaces, cornices, and stiffer snow to identify potentially wind loaded slopes. While we expect any avalanches to be small, consider the high consequences of a fall in steep terrain with exposed obstacles. 

    Due to difficult and long approaches, we have a lot of uncertainty about upper elevations, so be prepared to make your own assessments if you head into alpine terrain. Slick crusts, surface hoar, and weak snow surfaces are prevalent, so this new snow could bond poorly with old snow surfaces. Use quick hand pits or test slopes to see how the snow reacts. New snow that slides easily off old surfaces indicates that avalanches are more likely. 

    (12/2/2022)

    Drifts of snow like in this photo are an indication that winds slabs exist on the slope.

    Photo: Katie Warren

Avalanche Discussion

Well, the Christmas Day storm was a bit of a bust, and most locations in the East South picked up little to no new snow. The Bumping Lake and western portion of the HWY410 corridor picked up the most with 3 inches. Hopefully, the forecast for Monday night doesn't also underproduce, and we see an additional 2-4 inches of snow by Tuesday morning. Cold air pooled east of the Cascades could be eroded quicker in this southern area on Tuesday, and a transition to rain or freezing rain is possible. If it begins to rain on dry snow, expect rollerballs and small, wet loose avalanches. 

Temperatures have been warm over the past couple of weeks, and snowpack depths have decreased significantly. New snow may fall on bare ground on south facing slopes at mid and lower elevations. On others, there is plenty of brush to contend with. Rocks and boulders may still be exposed or barely covered with fresh snow. Consider staying on summer trails and roads to access higher elevations for more manageable travel.

You can contribute to the forecast! Let us know what you found by submitting an observation HERE. 

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