Bollettino valanghe

East Slopes South

Northwest Avalanche Center
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Pericolo valanghe

Thu
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
2 · Moderato
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Non aggiornato — questo bollettino è scaduto 4 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Wet and dry snow problems will be present as warmer weather invades the region. On upper elevation slopes and shaded aspects, wind-drifts may rest above a weak crust interface and you can trigger them on slopes 35 degrees and steeper. Adjust your aspect quickly to avoid triggering a small wet avalanche that could bury you in a terrain trap.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2

    A potent system over the weekend built potentially large slabs that are becoming stubborn to trigger. More recently, WNW winds continue to drift that snow proximal to ridgelines where you may find more reactive slabs just below sharp, fresh cornices. Milder temperatures and sunshine probably helped heal some of these slabs on aspects directly facing the sun. Any slab may rest on a weaker interface sitting above the MLK crust and may propagate more widely than you expect as a result. Steer around wind-loaded pockets steeper than 35 degrees; and avoid all steep slopes if you encounter shooting cracks or identify weak snow on top of the crust.

     

    (1/24/2023)

    Snowmobile triggered wind slab on 1/24 near the border of the Snoqualmie and East Central zone. 

    Public Field Report: Gold Creek

    Photo:

  • Loose Wet

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

    Wednesday may start with below-freezing temperatures, but it won't take long for temperatures to soar into the upper 30s and 40s with strong sunshine. Surficial crusts will break down, revealing sticky wet snow where you can trigger small wet loose avalanches on slopes 35 degrees and steeper. If you encounter rollerballs, wet avalanches may originate on the slopes above you. In all cases, adjust your aspect and seek cooler, shaded slopes.

Avalanche Discussion

NWAC forecaster Joe Dellaporta traveled to Norse Creek in the East South zone on 1/24. He found warm temperatures and warm, moist, gloppy snow. At 5300 ft on a SE aspect, around 10" of snow sits above a rounding facet / MLK crust interface that produced propagation in extended column tests. The 1/4 surface hoar can be found below the MLK crust, but did not propagate in tests. Another profile at 5100 ft on a S aspect consisted of mostly moist snow. Both profiles were shallow, 47" and 35" respectively. The focus of any avalanche activity is expected to be above the MLK crust. This crust deserves careful examination in your terrain. You can jump on small test slopes or make frequent, shallow hand shear tests to check the bond between the overlying slab and the MLK crust. If you find that bond to be poor, reduce your terrain selection to slopes less than 35 degrees and poorly supported slopes. 

Expect to find more wet, gloppy snow that may slow your travel on Wednesday. You may find shallow conditions at lower elevations with many hidden hazards, like exposed or barely covered rocks or stumps.  

If you get into the East-South, please let us know what you see by submitting a public observation! 

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