Bollettino valanghe

East Slopes Central

Northwest Avalanche Center
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Pericolo valanghe

Sun
Alta quota
3 · Marcato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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In sintesi

This won't be a big storm, but triggering a 2-4 foot thick avalanche remains a concerning possibility on upper elevation, northerly aspects. In these areas, give steep, rocky, wind-swept terrain some space on Saturday. Keep small wet avalanches in mind, especially in steeper consequential terrain. 

Problemi valanghivi

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    2–3

    Triggering a large 2-4 foot thick persistent slab remains a concerning possibility on the north side of the compass at upper elevations. While wind speeds will be light, we suspect this problem to be most dangerous in areas with fresh wind drifted snow, especially in locations with a more shallow snowpack. 

    So far, we have received confirmation from the Wenatchee Mountains that cold snow and, unfortunately, a weak snowpack continue to plague northern aspects (NW-N- NE aspects). We have limited information from other parts of the zone, but we suspect the EFC remains preserved elsewhere on northerlies above 6000 ft. 

    These avalanches can act surprisingly, often propagating widely or being triggered from a distance. You may or may not receive feedback before triggering this type of avalanche. The best way to reduce your risk of triggering one of these is by avoiding steep, rocky, wind swept terrain on the north side of the compass. 

    (3/6/2024)

    An example of a persistent slab release from a couple of weeks ago. 

    Photo: Anthony Lubetski

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–1.5

    As the day progresses, you may notice some rollerballing and even some small wet loose avalanches within the new snow. These slides will be small, but will be most pronounced during sunbreaks and during daytime warming. Give larger slopes some space if you start noticing rollerballs and pinwheels. You don't need a large avalanche to ruin your day in consequential terrain. 

    (1/28/2024)Photo: Katie Warren

    Small wet loose avalanches shedding off cliffs.

Avalanche Discussion

A spring storm will favor east slopes bringing enough precipitation to spike the avalanche danger, especially in areas that remained cold and dry without a crust. Wind will be exceptionally light, so slab formation should be limited to the highest ridgelines and exposed alpine terrain. 

While most slopes may have supportable thick surface crust,  we still have a bit of uncertainty about the slopes that don't, and the potential reactivity of the Early February Crust.  On 3/22, the Mission Ridge Pro Patrol reported weak snow and propagating test results on the EFC on shaded aspects above 6000 ft. They found this weak layer about 2-3 ft deep. Check out the video in the gallery for more information. On 3/20, an observer on Dirtyface Mountain reported a large whumph on an east aspect at 5700 ft. In this location, the surface snow was moist, but it serves as a reminder that weak layers are still lurking despite the recent warm-up.  During periods with higher uncertainty, the best strategy is to widen your margins. Give slopes that fit the description a wider buffer and carefully assess slopes before skiing, climbing, or riding larger slopes. 

On other aspects, the snowpack has endured a serious beating due to the recent warm-up. Observers have been reporting a variety of wet surfaces, supportable crusts, or even melted-out slopes on windward and steep solar aspects. 

Observations have been sparse. Help create a more accurate forecast by submitting your public observations here. 

 

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