Bollettino valanghe

Olympics

Northwest Avalanche Center
Vedi sulla mappa

Pericolo valanghe

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

In sintesi

We're entering a stretch of sustained mild temperatures that will last through the weekend.  Wet loose avalanches are the main avalanche problem to consider on steep southerly slopes Friday.  As we move deeper into the weekend, we may start to see an increased risk of cornice fall, glide cracks opening, or even an isolated larger avalanche. 

Problemi valanghivi

  • Loose Wet

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

    Warming temperatures and morning sunshine will try to break down the most recent sun crust on southerly and sunny aspects.  These weather factors will be competing against increasing cloud cover in the afternoon and a potential uptick in winds, so it's not a slam-dunk that wet-loose avalanches will materialize. 

    However, what to look for is pretty straight-forward; if you start to see the surface snow become wet, pinwheels, rollerballs, and/or small natural wet loose avalanches on steeper slopes, change aspects, move away from terrain traps where even a small avalanche could do damage or shift to lower angle terrain.  

     

    (1/9/2022)

    Example from last season of wet loose avalanches in Sunrise gully on a south-facing slope. 

    Photo: ONP Rangers

Avalanche Discussion

The last significant storm system rolled through the Olympics last weekend with about a foot of snow through Monday morning.  Lighter snow showers, cool temperatures, and periods of sunshine followed through Wednesday.  Older avalanche activity from earlier in the week consisted of generally small natural loose avalanches of both the dry and wet variety. 

On Thursday, the sun broke out and temperatures climbed to just above freezing with a light breeze at Hurricane Ridge.  Professional observer Sam Luthy found good stability and riding conditions on northerly/shaded aspects with settled cold snow.  Wind-affected snow was largely limited to exposed ridgelines and older wind drifted snow was unreactive.  Cornices in the Hurricane Ridge area were trimmed back and not particularly large.  On sunny slopes, a thick 2-3mm (1") sun crust overlaid 20-30cm (8-12") of drier snow.  The sun crust broke down as the day warmed and it was easy to ski trigger large pinwheels on steeper slopes in the afternoon. 

While all of this information points to a quiet and largely stable snowpack, you'll need to keep a larger picture in mind to stay safe as we move through the weekend.  Following weeks of cool, snowy weather we're going to see several consecutive days with milder temperatures, variable cloud cover and generally poor overnight refreezes.  Over in the Cascades, we've had large to very large avalanches release in higher alpine terrain in isolated areas, different aspects, and in very different parts of the range.  Region-wide, our snowpack is starting to transition from a layered cold snowpack and step into spring and there are some steps you can take to minimize your risk of getting caught in an isolated but larger avalanche.

 During this mild extended period:

  • Plan to limit your exposure to more complex, higher-elevation terrain where we know less about the snowpack. 
  •  Keep an eye out for subtle changes like growing glide cracks over the weekend. 
  •  As you move through different terrain and aspects, look up and be aware of your overhead exposure to steep slopes with large overhanging cornices.  

2022-2023 Forecast Schedule

NWAC will issue an avalanche forecast every Friday, Saturday and Sunday and every holiday mid-week day the Hurricane Ridge Road is open from December-early April.  We will issue Avalanche Watches or Warnings when conditions warrant. New for this season, we will not update the non-holiday midweek discussion.  Our mountain weather forecasts will continue to cover the Olympics and are issued twice a day through the end of April.  If you have questions or feedback, please contact us at [email protected] and [email protected]. 

If you're out in the snow, share your observations with us and your local backcountry community.

Regioni coperte