Avalanche forecast

West Slopes Central

Northwest Avalanche Center
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Avalanche danger

Tue
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

Natural and human-triggered avalanches have been reported over the last 3 days in many of our neighboring zones, including at least one burial where they luckily survived. Many of these avalanches failed on weak layers of snow beneath the new storm layer, 2 to 3 or more feet beneath the surface, and to avoid this problem, stay off steep slopes. It's also likely you could trigger a shallower avalanche in layers closer to the surface. 

Avalanche problems

  • Storm Slabs

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

    You can trigger storm slab avalanches in the snow that's falling Sunday night. Avalanches may fail within this new layer only a few inches deep, or near the bottom of the overnight snow, which could be closer to a foot, or slabs could fail within any number of storm instabilities in the upper portion of the storm layer that began Thursday night and totals 2.5 inches of water and almost 3 feet of snow.

    These storm slab avalanches could come in any variety of flavors: Light, fluffy slabs that recently fell could release with a human trigger, or maybe even naturally. Wind slabs will exist in some areas, and may be deeper. You can identify textured or pillowlike, thicker-feeling deposits.  It'll be easier to trigger an avalanche on a wind-loaded slope. Sluffs, or dry loose avalanches, could occur naturally or with a human trigger. 

    With all of these concerns- and the following Persistent Slab problem - the advice is the same: Avoid steep slopes. If you were just looking at these newer, shallower storm instabilities, you might be able to step out in steep terrain if you know how to manage it, but given deeper underlying layers of concern, that isn't a wise option right now. 

    (2/1/2025)

    An intentionally triggered small storm slab. 3-12" deep, and 20 feet wide. SS-ASc-D1-R2-S, NE, 6200ft, similar to what you might see on Monday. 

    Photo: Dallas Glass

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–2.5

    There's no point beating around the bush- we've got a dangerous Persistent Slab avalanche problem out there friends. 

    • You could trigger an avalanche that could fail in weak, faceted snow or on slick snow beneath the new snow layer, what we've now dubbed the "January Drought Layer" or JDL. Several avalanches have failed on this layer already: human-triggered and natural. Crowns could be 2-4+ feet deep! 
    • Avalanches could also fail on the 1/10 crust, which is about 8 inches beneath the new/old interface, resulting in an even larger, unsurvivable avalanche.
    • Avalanches could surprise you by propagating wide or traveling far back into lower-angle terrain above the start zone. They also might be triggered or break lower in the path than expected. 
    • Depending on where you are in the zone, other underlying weak layers may also come into play. Alternatively, some spots may not have as much of a problem.  
    • These weaknesses are a concern where there was less rain and the new snow is deeper, generally above 4000ft. 
    • The extent of these weak layers is very inconsistent, so digging a pit in one spot or skiing one slope doesn't mean it's safe a few feet away. 

    To manage this problem, avoid all steep slopes. If you see natural avalanches, experience whumphs, or remotely trigger avalanches, avoid all avalanche terrain including where an avalanche runs and stops. 

    (2/2/2025)

    This avalanche released after a audible whumpf. The slide failed on facets over a crust and released the entire width of the feature. NE, 3700ft

    Photo: Summit at Snoqualmie Professional Patrol

Avalanche Discussion

Any shallower storm slab avalanches you trigger could provide the added weight to step down and release a much scarier persistent slab avalanche. If, for some reason, you decide to step out into steeper terrain, increase your chances of survival by having a partner, only expose one person at a time to the slope, and be equipped with a transceiver, shovel, and probe. Know how to use your rescue gear and practice regularly so that you can quickly dig your friend out before they die of asphyxia, if they didn't die from trauma first. This option is not recommended.

I was in the Monte Cristo area Sunday morning. There was 3" of new snow to 4000' but by 4500' there was 2ft! I didn't see or trigger avalanches, although visibility was poor and my sample size was small. Pit test results yielded concerning unstable results on the January Drought Layer and the 1/10 crust, which confirmed by hesitation to travel on steep slopes. You can read my observation HERE.

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