Bollettino valanghe

Snoqualmie Pass

Northwest Avalanche Center
Vedi sulla mappa

Pericolo valanghe

Fri
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
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

Thursday’s avalanche hazard will depend on competing weather factors trying to influence the snow’s surface. Warm temperatures and sunshine will attempt to destabilize the snowpack. When you find a wet, sticky, or punchy surface seek our more frozen or lower angled terrain to avoid the hazard.

Problemi valanghivi

  • Loose Wet

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

    Warm temperatures and a strong April sun will compete against possible clouds and a cooling breeze to influence the snow surface. If you find a strong overnight refreeze this process may take longer and help limit the avalanches hazard. However, if you encounter a weak, thin, or breakable crust in the morning, you may see the surface change rapidly. Pay attention to the snow as travel. When you begin to sink past your ankle, notice new rollerballs, or experience a wet, sticky, or punchy surface it’s time to go somewhere else. These clues should cause you to seek out more frozen or lower angled terrain. Expect wet snow conditions to develop in the morning on easterly facing slopes before expanding to other aspects as the sun moves across the sky and temperatures warm. Wet snow conditions could even spread to more shaded slopes which still harbor drier snow over a recent crust. Only the highest shaded features might escape this period of warm weather. While loose wet slides may feel predictable, they can still get you into trouble in large or high consequence terrain. 

    We believe that increasing clouds and cool breeze will help confine the avalanche hazard Thursday to only specific steep rocky features. However, dangerous conditions could develop if poorly frozen snow combines with very warm weather and sunny skies. If you notice numerous small loose wet slides occurring or see larger events, dial it back give avalanche paths a wide berth.

    (3/31/2021) Sunshine and steep rocky slopes often result in rollerballs like these. When you see this observation start to anticipate loose wet avalanches on similar aspects. Kendall Lakes, Sw 5300' Photo: Dennis D'Amico

Avalanche Discussion

You will find the lowest avalanches danger in the morning before the weather has a chance to impact the snow. As the day progresses you could see different avalanche danger on different aspects. Constant observations will be needed to recognize when conditions change.

A recent storm Sunday/Monday brought 8-15” of snow and strong sustained winds to the Pass. This resulted in a variety of snow surfaces including scoured crusts, deep drifts, and wind packed snow. At upper elevations and in wind-affected areas this should help reduce the chance for loose avalanches. In most locations, this recent snow sits atop a firm crust (3/28). Avalanches occurring over this smooth surface may run far and fast. 

Cornices grew large and overhung along many ridgelines during this winter’s stormy weather. Warmer periods like this cause us to wonder if they may begin to fall down. Choose routes that help limit the amount of time you spend near or under these looming waves of snow. Collapsing cornices and loose slides could serve as triggers for slab avalanches on the slopes below. Many layers still linger in the snowpack that may produce isolated large avalanches. Despite the spring-like weather, the snowpack has not yet fully made its transition. 

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