Bollettino valanghe

West Slopes South

Northwest Avalanche Center
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Pericolo valanghe

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

In sintesi

Multiple days above freezing combined with liquid water moving through the snowpack will maintain the potential for wet avalanches on Tuesday. These slides are difficult to predict and can fail without warning. Make travel plans that put plenty of space between you and sagging blocks of snow.

Problemi valanghivi

  • Wet Slabs

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

    Liquid water is still working through the snowpack, temperatures are unseasonably warm, and not every slope or rocky ledge has shed over the past week. Until the surface starts to freeze, there is a potential for lingering wet avalanches. This includes - slabs, loose, glide, and cornice.  You should watch for sagging cornices, glide cracks, or precariously perched blocks of snow. They could fail without warning, possibly triggering additional slabs or loose avalanches on the slopes below. Give these unpredictable time bombs a wide berth as you travel. 

    (1/28/2024)

    An explosives-triggered avalanche at Crystal Mountain that propagated widely while exposing rock and dirt.

    [N 6700' WS-AE-R3-D3-O]

    Photo: Crystal Mountain Pro Patrol

Avalanche Discussion

On Monday, the West South zone burned some vacation time and made a trip to the tropics. Temperatures soared into the 50s at most NWAC weather stations. On Mount St. Helens, our station hit 66 degrees! The sun even came out here and there as we reached the apex of our unseasonably warm week. NWAC stations have been above freezing since Friday morning. 

During this period, a significant wet avalanche cycle occurred throughout the zone. NPS rangers at Paradise spotted some very large avalanches on Monday. They may have been a subset of the slides reported by the USGS on Saturday. Further south, numerous large to very large avalanches were reported on Mount St. Helens. White Pass Pro Patrol reported widespread rain runnels and wet avalanche debris on most steep slopes. 

Throughout the weekend, Crystal Mountain Pro Patrol triggered very large avalanches with explosives. Some propagated widely and failed in old snow layers, gouging down to expose rocks and dirt. Many of these are suspected to have failed on our deeper layers of concern, such as the Solstice Crust or 12/30 interface. During a period of visibility on Sunday morning, multiple natural avalanches were spotted in the terrain surrounding Crystal. 

Expect another warm day with some drizzle on Tuesday. Temps are slowly lowering back toward seasonal norms, but you may not notice it for a few days. A last pulse of rain will impact the zone before we finally cool down on Thursday. 

Travel conditions may be difficult due to runneled snow surfaces, open creeks, and unconsolidated wet snow. You could even encounter bare ground at lower elevations or on previously wind-stripped ridgelines. 

Regioni coperte