Bollettino valanghe

West Slopes North

Northwest Avalanche Center
Vedi sulla mappa

Pericolo valanghe

Sun
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
2 · Moderato
Open full map
Non aggiornato — questo bollettino è scaduto 5 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Incoming snow will be redistributed by strong winds and fresh slabs could be easy to trigger on wind-loaded slopes greater than 35 degrees. Carefully evaluate how new snow bonds to old snow surfaces. Bring a cautious mindset and ease into terrain slowly. 

Problemi valanghivi

  • Wind Slabs

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

    A cold, windy storm will bring another 8-12in of new snow over the next 24 hours, adding to the 16in of recent snow from Wednesday night. Wind slabs that formed earlier in the week still have not healed, and the incoming storm will thicken existing slabs and build new and more reactive slabs. Expect increasing avalanche danger as you gain elevation and transition into wind-affected terrain. Human-triggered avalanches are likely on wind-loaded slopes 35 degrees and steeper near and above treeline. These avalanches could break 1-2ft+ deep within layers of new and wind drifted snow or on a crust buried during the last storm (4/7 interface). You may even find strong westerly winds drifting snow and stiffening slabs in areas below treeline. 

    Gather plenty of information as you travel and think twice before committing to consequential routes. Use test slopes and hand pits to assess how new snow is bonding to old snow surfaces looking for sudden or easy failures. Recent avalanches, cracking, and collapsing are clear signs of unstable snow and should direct you to lower-angle terrain away from overhead hazard. 

    Example photo of shooting cracks in wind drifted snow.

Avalanche Discussion

Several near misses occurred over the past week throughout the region including human-triggered wind slab avalanches in alpine terrain and close encounters with large natural glide avalanches. Fortunately, there were no full burials or injuries. The back and forth between winter and spring continues to bring spikes in avalanche danger and rapid change. Expect dynamic conditions over the weekend, and be thoughtful and cautious with your terrain and travel choices. 

Friday night's storm looks to be similar to Wednesday's, but windier and cooler. Light snowfall may linger through the morning, with cloudy skies in the afternoon. Incoming snow may not bond well to old snow surfaces initially and could be easily triggered by the weight of a person in steep, unsupported terrain. If the clouds break unexpectedly, watch for wet loose avalanches on sunny slopes. 

Continue to identify and avoid cornices. They grew large throughout the winter and will be tested again by new snow, wind, and sun this weekend. Stand far back from these features along ridges, and avoid travel on slopes below. Plenty of glide avalanches occurred over the past week during periods of sun and warming. Cool snowy weather Saturday will limit any additional glide activity, but keep these avalanches in mind for Sunday and during the week ahead. 

During the ongoing Covid-19 pandemic, continue to follow the latest guidance from local, state, and federal health officials. Avoid unnecessary risks that could impact first responders and stress medical resources.  Wear a mask when appropriate, practice social distancing, and consider recreating closer to home.

Regioni coperte