Bollettino valanghe

Olympics

Northwest Avalanche Center
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Pericolo valanghe

Wed
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In sintesi

More sunny weather and warm temperatures will allow a springtime shedding cycle to continue on Tuesday. Once the snow surface has softened up and you are sinking into the snow past your ankle, it may be time to head toward shadier slopes.

Problemi valanghivi

  • Loose Wet

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

    Temperatures will again start to climb on Tuesday, reaching higher freezing levels than they did on Monday. The nice weather should allow wet avalanches to develop on steep sunny slopes as the snow surface starts to soften. Your first indicators that the upper snowpack is destabilizing will be rollerballs and pinwheels and the surface becoming wet and sticky. If you notice these signs, expect Wet Loose avalanches to follow and head toward shadier slopes. These slides often start at a point such as near trees or rocks, can entrain significant snow, and will fan out as they descend, possibly growing large and traveling long distances toward lower elevations. 

    (2/28/2021) Rollerballs such as this will be one of your first indicators that the snow is destabilizing and Wet Loose avalanches may follow.

  • Wind Slabs

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

    Slopes that do not see direct sunshine could still be harboring cold and dry snow, much of which may be wind-affected. The winds should increase slightly on Tuesday and may transport some of this dry snow to form fresh slabs, or you could find a lingering slab from the weekend. Take a look for textured snow surfaces or pillow-like piles of snow to help you identify wind-loaded slopes to avoid. They will be more likely as you ascend in elevation and often form near rocky features such as confined gullies or at the base of cliffs. You should also look for them on leeward slopes near ridgelines or on convex rollovers. In areas with dry snow, you can use uptrack tests or test slopes to determine the slab potential and if blocks of snow are failing easily. If you find poorly bonded snow or suspect a terrain feature to be wind-loaded, you should seek out lower-angled options.

    (4/10/2021) Multiple human-triggered avalanches occurred at Hurricane Ridge on Saturday (4/10). These slides were 6-12" deep and were running easily on the recent crusts [E 5400' Photo: Joe Carpenter]

Avalanche Discussion

The snowpack around the Olympic Mountains is in a state of flux and both wet and dry avalanches pose a hazard right now. Most slopes have been receiving direct sunshine and should be going through a melt-freeze cycle due to cool nights and warm sunny days, creating a firm surface crust. This crust may grow thicker throughout the week, but below it you will still be able to find cold dry snow.  As the snow surface softens throughout the day on these sunny slopes, expect a continuation of the springtime shedding cycle that started on Sunday and is expected to produce wet avalanches, snow falling off trees or rocks, and cornice collapses. This cycle will go through peaks and valleys over the next week as sunshine, freezing levels, and cloud cover fluctuate with the springtime weather. A good public observation relayed a cornice collapsed on Mt. Ellinor and triggered an avalanche on the slopes below, proving that this cycle has already begun. Choose safe travel routes far away from overhead hazards such as cornices or other large blocks of snow, and take into account your return route when planning your trip for the day. 

On slopes that do not see direct sunshine, a colder and more layered snowpack may exist. The 4/7 and more prominent 4/9 interface should act as snowpack markers for you and we expect all avalanches to occur above the 4/7 interface, whether they are wet or dry. Over the weekend, multiple human-triggered avalanches occurred in the recent storm snow at Hurricane Ridge, failing and running on these interfaces.

Spring Forecast Schedule:  NWAC will issue a danger rating every day for the Olympics beginning Friday, April 2nd  - Sunday, April 18th. 

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.

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