Avalanche forecast

West Slopes South

Northwest Avalanche Center
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Avalanche danger

Sun
Alpine
4 · High
Treeline
4 · High
Below
3 · Considerable
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Out of date — this forecast expired 3 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Multiple feet of incoming snow will result in very dangerous avalanche conditions on Saturday.  Natural and human-triggered slides are expected throughout the weekend. Fight the urge to head right into avalanche terrain - this is not the time.

Avalanche problems

  • Storm Slabs

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

    You are very likely to trigger avalanches on slopes over 35 degrees and natural avalanche activity is expected on Saturday, particularly in the morning hours. Deeper slabs are expected on the volcanoes where higher snow totals are anticipated. Closer to the crest, a weaker snowpack structure is suspected, which may make it equally as dangerous. In isolated areas, avalanches could involve much of the snow received so far this season. Travel in avalanche terrain is not recommended at this time.

    (12/1/2023)

    Example: This avalanche failed at the new/old snow interface on Friday in a different forecast zone. Expect similar activity on Saturday in the West South. SS-ASc-R2-D1.5-I

    Photo: Irene Henninger

Avalanche Discussion

Well, this is a tricky first day to dust off my writing skills. Welcome to winter and our first major storm cycle! Many of us have been waiting patiently to get back into snowy mountains to recreate. Unfortunately, Saturday should not be that day. Very dangerous avalanche conditions are expected throughout much of the zone and travel in avalanche terrain is not recommended. This includes closed ski areas where avalanche mitigation is not currently taking place. 

As of Friday evening, storm totals range from 6-10” near the crest to over a foot on the volcanoes. Expect these totals to double or triple by the time Saturday ends. [Paradise is forecasted to receive 3” of water in the next 24 hours.] This snow is falling on a variety of surfaces, primarily a melt-freeze crust, creating the 11/30 interface. We suspect the majority of avalanche activity to occur here. However, prior to the storm, a weak snowpack structure was observed by an NWAC forecaster near Crystal Mountain. A stronger snowpack was found the next day at Paradise. This has led to uncertainty around which areas of the zone are more prone to deeper, surprising avalanches this weekend. Our suspicion is that areas closer to the crest had a weaker snowpack prior to the storm than on the volcanoes.

Despite the new snow, natural hazards such as boulders, shrubs, open creeks, and holes will still exist. Because of them, getting caught in an avalanche, regardless of size, could be consequential. Try to temper your excitement and show some restraint. Many avalanche accidents occur in the early season when snowpacks and intimate knowledge of them are thin.

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