Avalanche forecast

West Slopes South

Northwest Avalanche Center
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Avalanche danger

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

A wide variety of avalanches are in the cards for Sunday. Unstable slabs of wind drifted snow can be found in many areas while sun breaks could trigger a round of wet avalanches. When in doubt default to lower angle, simpler terrain to reduce the risk of triggering an avalanche or being overrun by one from above.  Deep snow hazards still exist, especially where you could fall into a tree well or some other terrain feature. Stick with your partners and keep them in sight at all times.

Avalanche problems

  • Wind Slabs

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

    Strong east winds hammered parts of the zone and built fresh wind slabs. Active loading will back off but the recent crop of slabs will still be a hazard Sunday. The distribution and reactivity of unstable wind slabs will vary across the zone. Evaluate terrain on a case-by-case basis - some slopes could be just fine with others a definite no go. 

    Well established cornices and other clues that show the usual direction of wind loading - normally from the south and west - will be less useful to determine where fresh wind slab lie in wait. Instead look for smaller, sharper cornices, recently scoured ridgelines with smooth, fat, or pillowy-looking drifts on the slope below. Test slopes and hand shears will help gauge wind slab reactivity and depth and can help you identify areas where they are easier to trigger. 

    (3/4/2023)

    Strong winds, intense wind transport and cornice formation on Saturday.

    Photo: Andy Harrington

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    The likelihood of seeing wet avalanche activity will vary widely on Sunday, but if the sun comes out signs of instability and eventually wet avalanches will follow. This is especially the case on the volcanoes with more sun destabilizing greater amounts of new snow. If you don’t see the sun you probably won’t see much in the way of wet avalanches.

    Pay attention to slopes overhead and look for initial signs of instability like snow shedding from trees and rocks. Pinwheels or balls of snow rolling down the slope are also telltale signs of warming. If you see these it would be a great time to give a wide berth to slopes that face the sun. Though initially small, wet avalanches could grow in size or trigger a slab avalanche lower on the hill and run farther than expected. 

    In addition to wet avalanches, you can still trigger sluffs in steep terrain holding soft, cold snow. Warming could also create shallow slabs that are reactive to the weight of a person.  

    An example of natural rollerballs, loose wet, and small wet slab avalanches.

    Photo: Dallas Glass

Avalanche Discussion

Some variation on stormy conditions was reported from around West South today. Both Crystal and White Pass saw strong east winds and wind transported snow with “knock you over” winds at Crystal. Fresh slabs began to build by midday and became easy to trigger. Both areas saw about .75” of precipitation equalling 8” or more of new snow. 

Continued snowfall was the story on the volcanoes with the Swift Creek Snotel near Mt. St. Helens picking up 22” of new snow in 24 hours. Natural slab avalanches were reported from Paradise in steep, unsupported terrain along the Paradise Road.

Regions covered