Avalanche forecast

West Slopes South

Northwest Avalanche Center
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Avalanche danger

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

The weather is easing some, but snowfall and wind-loading continue to elevate the avalanche danger. Avalanche likelihood and size increase with elevation, higher storm totals, and wind exposure. Approach terrain cautiously, treat steep slopes as suspect, and consider steering clear of wind-loaded areas at higher elevations.

 

Continued heavy snow and wind are creating more dangerous conditions on Mount St. Helens and Mount Adams than elsewhere in the West South. Consider reading the Mount Hood Forecast for a more representative reflection of the current avalanche conditions in these areas.

Avalanche problems

  • Storm Slabs

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

    Snowfall totals are expected to vary significantly across White Pass, Crystal, and the Volcanoes. In areas receiving less snow Sunday night into Monday, wind-loaded slopes will be the main concern, as they may still harbor deep and unstable slabs. In zones with more snowfall, stability should be assessed on all steep slopes, regardless of whether you see signs of wind loading. Pay attention to the bond between the new snow and underlying surfaces and check for weak layers within the storm snow. While most avalanches will likely involve snow from Sunday and Monday, deeper slides down to the Solstice Crust remain possible, especially in wind-loaded terrain at higher elevations. Tread carefully around unsupported terrain, slopes below sharp ridgelines, convex rollovers, and gully entrances where slabs tend to lurk.

    Consider adjusting your plans in areas with more fresh snow unless you are confident in your stability assessment. Look for slabs by feeling for hard-over-soft layers and watching for signs like blowing snow, textured surfaces, or chalky drifts. Before committing to steep terrain, conduct hand pits, uptrack tests, or use safe test slopes to check stability. Red flags, such as shooting cracks or recent avalanches, indicate dangerous conditions and should lead you to avoid steep terrain. Keep in mind these informal tests only provide information as deep as your hand, ski, or sled can dig. In wind-loaded areas, the safest approach is to give the snowpack another day to stabilize under its new load.

    (12/26/2024)

    A large (D2) slab avalanche that occurred naturally in steep rocky terrain at Crystal Mounain on 12/26. This type of terrain remains suspect on Monday.

    Photo: Crystal Mountain Pro Patrol

Avalanche Discussion

The Christmas storm continued to deliver for White Pass and the volcanoes on Sunday, while conditions eased at Crystal. Multi-day storm cycles with shifting temperatures, wind, and differing quantities of precipitation across the zone compound the uncertainty heading into Monday. Simply put, conditions on the ground will depend on what has happened over the past few days in the zone you are travelling. Be prepared to make your own assessment and for local conditions to differ from the zone-scale avalanche forecast. In general, expect increased avalanche danger in areas with continued loading, both in and outside of the wind zone.

On Sunday, NWAC forecasters and Crystal Pro Patrol reported fairly stubborn reactivity and noted just a few signs of instability in isolated and small wind-loaded pockets. The general opinion was that storm instabilities had largely settled out. We like to hear that. Still, those observations are tempered by the higher snow totals elsewhere in the zone and a recent report of a human-triggered avalanche near Paradise.

Over the next two days, decreasing snowfall and diminishing winds should further improve stability in parts of the zone that get a break from all this loading (meaning Crystal, not St. Helens!). In those locations, we expect wind slab avalanches to be the primary issue. Wind slabs typically require more time than storm slabs to heal and with plenty of fresh snow available for transport on Sunday night, the loading has likely not yet subsided on these slopes.

Let the weather and your senses help guide you tomorrow. Check NWAC weather stations in the morning and assess the snow depth once you are in the mountains. If you see lots of fresh snow, make more conservative decisions. If you find yourself in calm weather and are considering a bigger objective, ease into the terrain so the snowpack has a chance to talk to you in lower consequence terrain before you dive into something bigger. With all the fresh snow, tree well and Snow Immersion Suffocation are becoming real hazards. Keep sight of your partner at all times!

Enjoy the break in the action Monday and Tuesday and please send us an observation if you make it out!

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