Bollettino valanghe

West Slopes Central

Northwest Avalanche Center
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Pericolo valanghe

Fri
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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Non aggiornato — questo bollettino è scaduto 6 months ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

You should find increased avalanche danger anywhere 6 or more inches of new snow has accumulated. Assess the bond of new snow layers before heading onto steeper slopes. When in doubt, stick to lower-angle, less wind-exposed terrain.

Problemi valanghivi

  • Storm Slabs

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

    While most parts of the Cascades picked up an inch or two of snow at best, parts of West Central received 4–8 inches of new snow early Wednesday morning. The most snow is likely west of Index, extending into the Mountain Loop area and possibly beyond into North Cascades NP.

    This new snow is adding load to weak snow surfaces that were first buried by a few inches of snow around Valentine’s Day. This latest storm, however, may have created a thicker slab above that layer. You are more likely to trigger an avalanche on slopes with recent wind loading, but instability is also possible in steep, wind-sheltered terrain.

    Hand pits and small test slopes can help assess how well the new snow is bonding. Shooting cracks, whumphing, and recent avalanches are clear red flags that human-triggered avalanches are possible in steep terrain.

    Where the snow remains soft and fluffy, expect loose snow to move with you on steep slopes.

    Example of a very small but steep feature used to test stability.

Avalanche Discussion

The balance between sun and temperature should limit wet avalanche activity on Thursday, but don’t rule it out entirely. Pay attention to sunny slopes overhead and watch for wet avalanche indicators like rollerballs or pinwheels.

West Central is in a unique spot compared to surrounding forecast zones, having picked up significant snow while other areas saw only a trace to an inch—or nothing at all. This is likely due to the Puget Sound Convergence Zone. It’s beyond the scope of this forecast to explain, but it’s worth looking up if you’re interested in how weather and snowfall vary across the Cascades.

Convergence-zone–enhanced snowfall added at least 6 inches at the White Chuck Tripod near Darrington, and even low-elevation stations got in on the action, with 7 inches reported at Alpine Meadows just south of Gold Bar on Highway 2. As usual, precipitation and snowfall decreased farther east toward the Cascade Crest.

The primary layer of concern is the old snow surface buried by a few inches of snow on February 13. While there are no snowpack observations from West Central, buried surface hoar and weak faceted snow have been found at this interface in Stevens, Snoqualmie, and West North. This layer is not thought to be widespread or highly active, but it’s worth keeping on the radar after this unexpected load of new snow.

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