Avalanche forecast

East Slopes South

Northwest Avalanche Center
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Avalanche danger

Thu
Alpine
2 · Moderate
Treeline
1 · Low
Below
1 · Low
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Highlights

Cold temperatures and steady light to moderate winds may build new slabs in wind-drifted snow. Watch for blowing snow and steer around deep pillows of snow in steep terrain near ridgelines. More frigid temperatures are in store for Wednesday, so bring some extra layers to prevent cold injuries.

Avalanche problems

  • Wind Slabs

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

    There is plenty of low-density snow available for wind transport by the forecasted light to moderate winds. If you venture into the highest elevations, you may be able to trigger newly formed wind slabs in isolated areas. While existing wind slabs are likely gaining strength, new and sensitive wind slabs might form on lee aspects. With a forecasted shift in wind direction, slabs could develop on atypical aspects. Be attentive and watch for signs of pillow-like, hollow snow near ridgelines at upper elevations. If you experience shooting cracks or see recent avalanches, choose lower angle terrain. 

    With snow depths tapering from west to east from the Cascade Crest, expect that larger and more sensitive wind slabs may reside in the northern portion of the zone and areas closer to the crest. 

    Small wind loaded features at ridgeline can serve as test slopes to gauge the reactivity of fresh wind slabs.

    Photo: Lee Lazzara

Avalanche Discussion

Many of these eastern areas still have exposed rocks and trees, and the deepest snowpacks are around Mt Aix and Bumping Ridge. The solstice crust is buried approximately 2-3 feet deep near the Cascade Crest and 5-6 inches deep in the eastern parts of the zone. Current reports indicate that the storm snow is bonded well to the solstice crust. However, we have limited observations from the upper elevations, resulting in significant uncertainty about snowpack conditions in alpine areas. There have been reports of weak snow surrounding the December 8th melt-freeze crust in neighboring zones. It is worth approaching new terrain slowly and evaluating the snowpack as you venture into higher elevations.

Some light snow overnight on Tuesday may transition into a sunny day for Wednesday, with continued bitterly cold temperatures. The cold temps will likely limit any potential for wet avalanches on solar aspects, but you may observe small dry loose avalanches in very steep terrain. While these avalanches may be small, terrain traps and extreme terrain can significantly increase the consequences. 

With a forecasted return to stormy weather on December 30th, tomorrow is a great day to take note of the surface conditions where you travel. Cold temperatures and clear nights may have developed weak, faceted snow or surface hoar. On Wednesday, the sun may form thin surface crusts on steep sunny slopes. The current snow surface could be a new weak layer or bed surface when we receive additional snow. Use our observation page to let us know what type of snow surfaces you find. 

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