Bollettino valanghe

West Slopes North

Northwest Avalanche Center
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Pericolo valanghe

Fri
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
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

Deep, wet snow is still making for dangerous avalanche conditions and difficult travel. Minimize time spent on and under steep terrain until the snowpack begins to consolidate with cooler temperatures. Avalanches in drier new snow layers are possible in the alpine.

Problemi valanghivi

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1.5–2.5

    Continued rainfall produced another round of natural and human triggered wet avalanches Wednesday morning. The upper 2-4’ of snowpack over the Valentine’s Day Crust is wet, unconsolidated, and weak. Ski cuts on steep slopes continue to trigger loose wet avalanches that get larger and larger until they stop in flat terrain. Natural wet slabs, glide avalanches, and falling cornices also remain a concern and could entrain large amounts of snow despite starting off small.

    Slightly cooler temperatures Thursday should decrease the likelihood of encountering one of these avalanches. On the other hand, they will still be dangerous if they get moving. Avoiding these is not a timing issue - simply being in or directly under steep terrain puts you at greater risk. Periods of sun in the afternoon could trigger a round of rollerballs, large pinwheels, and small loose wet avalanches on sun exposed aspects

    (3/2/2022)

    Wet avalanche debris on Iceberg Lake below Table Mt in 2018. Poor weather has prevented clear observations of recent avalanche activity.

  • Storm Slabs

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

    In the last 4 days, alpine areas picked up 6-12” of precipitation that fell mostly as snow, especially above 6000’. This created deep slabs that formed over old, weak snow surfaces. It’s likely many of these paths avalanched naturally and the rest are adjusting to the load of new snow but unstable slabs could still be found. Anticipate higher danger on wind loaded slopes. If you make it to the alpine on Thursday give large unsupported terrain features a wide berth. Plan on bypassing this sort of terrain for a few more days as new snow layers strengthen and stabilize.

Avalanche Discussion

The widespread, natural avalanche cycle peaked a few days ago but avalanche activity continued through Wednesday. Dozens of avalanches of all types and sizes to D3 were reported from the Baker Backcountry despite poor visibility and limited observations. Anybody simply driving up to Heather Meadows could see multiple crowns on Mt. Herman as they turned right onto the one-way loop at Picture Lake. Whereas other regions of the Cascades have seen precipitation slack off and the snowpack beginning to consolidate, this area has continued to pick up 2-3” of precipitation every 24 hours. Less precipitation and slightly lower snow levels are forecast for the next 24 hour period.

No observations have been submitted from other areas in West North, likely due to poor weather and terrible snow conditions. The common theme amongst avalanche professionals across the Cascades has been to minimize downhill travel through knee-wrenching deep, wet snow on observation tours.

The upper snowpack near treeline consists of up to 130cm of storm snow over the prominent crust layer buried on February 14th. The top 30cm is wet melt forms and other wet snow layers can be found deeper in the snowpack between layers of moist, rounded grains. Cooler temperatures should bring about a rapid increase in strength but it will take more than one or two cold, clear nights for the snowpack to fully freeze and consolidate.

Regioni coperte