Bollettino valanghe

West Slopes Central

Northwest Avalanche Center
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Pericolo valanghe

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

In sintesi

You can trigger and get caught in large, dangerous avalanches as snowfall and wind continues.  Avalanches are most likely to occur on steep slopes where wind drifted snow into thicker pillows, but enough snow fell in the last 48 hours to warrant exercising caution on all steep slopes. Steer around steep terrain on Tuesday, and stick to lower angle slopes as the snowpack adjusts to the added weight. 

Problemi valanghivi

  • Storm Slabs

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

    Several backcountry users were caught and carried in slab avalanches over the weekend in neighboring zones. Considerable danger means human-triggered avalanches are likely, and it is important to evaluate terrain carefully. The avalanche involvements were smaller wind slabs, and we've since received at least a foot of snow, especially in the northern half of the zone, and we'll likely receive another foot+ by the end of the day Tuesday. The problem has shifted into storm slabs, as there is enough new snow coating all steep surfaces that wind-loaded or not, it is likely that you could trigger an avalanche. Expect wind-loaded areas to be more sensitive.  Even at lower elevations where snow hasn't fallen by Monday, there might be enough snow that falls by Tuesday to trigger avalanches at the upper reaches of below treeline elevations. 

    No matter where you travel on Tuesday, it's up to you to make decisions on where it is safe to go. Evaluate the snow constantly as you travel, and pay attention to obvious clues such as cracking , whumphing, and recent avalanches. These are clear indicators a steep slope is ready to slide.  Areas of thickly deposited new snow could use some adjusting, especially where wind loaded. Even locations with shallower new snow layers could still harbor reactive slabs that could take you for a ride and injure you, if not bury you. The likelihood of triggering large slabs in the backcountry right now, ones that are big enough to bury and kill you, is enough of a concern that your best option is to avoid traveling on slopes steeper than 35 degrees.  If you notice any natural avalanches or find conditions warranting more caution, steer around the bottom of avalanche paths as well. 

     

    You could trigger thick, unsurvivable slab avalanches in the backcountry on Tuesday. 

    Photo: Public Observation

  • Loose Wet

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

    A wet loose avalanche cycle with avalanches up to D2 (Large) occurred in the neighboring Stevens Pass Zone on Monday. Dropping snowlines means moist snow will accumulate in below treeline areas, and this is where we might see rollerballs and small wet loose avalanches. They will probably run in any new snow that falls, as the old snowpack is well adjusted to warm temperatures and rain already. Avalanches might easily be able to run on the old snow surface, however. If you find conditions where it's easy to kick off rollerballs or small avalanches, natural or not, steer around nearby steep slopes and away from beneath the steep slopes. 

    (3/13/2022)

    Wet loose avalanches were easy to trigger in the last 2 days.

    Photo: Public Obs

Avalanche Discussion

Limited information is known about conditions in the West Central Zone at this time, but plenty of observations from neighboring zones exist. If you're planning on heading out, check neighboring zones, as conditions vary greatly from one side of this zone to the other and similarities likely exist with the neighbors.

There is uncertainty about how continued snowfall and wind will strain the existing layers- maybe as temperatures cool the snowpack adjusts to the new load, or conditions could be more spicy than expected. There's a chance natural avalanches could occur, probably overnight and early morning as snowfall rates peak.  It's important that you evaluate conditions carefully and make decisions before making your way out into avalanche terrain on Tuesday. 

Regioni coperte