Lawinenlagebericht

Olympics

Northwest Avalanche Center
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Lawinengefahr

Tue
Hochgebirge
4 · Gross
Waldgrenze
4 · Gross
Unterhalb
4 · Gross
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Kernpunkte

Very dangerous avalanche conditions will continue through Monday.  Large avalanches may break in surprising ways and run far distances.  Avoid travel in or below avalanche terrain. 

Lawinenprobleme

  • Persistent Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Very Likely
    Größe
    2

    New snow will continue to stress deeper weaker snow layers Sunday night and Monday.  Slab avalanches may fail within new storm layers or break down 2 feet or more to weak snow over the 1/13 crust.  Persistent slab avalanches are very dangerous, surprising, and difficult to predict. They can propagate widely across terrain features and can result in large and deadly avalanches.  Make sure to stop and regroup in places that are well away from and out from under avalanche paths. Stay alert to signs of instability such as recent avalanches, shooting cracks, and whumphing collapses.   

    (1/30/2021) Human triggered persistent slab avalanche stepping down to 1/13 crust. Estimated to be size D1.5. North facing aspect near Victoria Overlook. Photo: Ashley Turcotte - NPS

Avalanche Discussion

NWAC issues avalanche warnings on "No Rating" days when we anticipate High avalanche danger in many areas.  

As of 6 pm Sunday,  roughly 20" of snow has accumulated at Hurricane Ridge since Saturday night with another 1-2' expected through Monday.   

Weather models and weather forecasters alike have had a challenging time wrapping our heads around how much snow will fall in this pattern.  If the current forecast holds, heavy new snow could lead to a natural avalanche cycle Sunday night and Monday.   Given how sensitive conditions were on Saturday, this is a good time to err on the side of caution and avoid all consequential terrain on Monday.  

On Sunday afternoon, a small natural slab avalanche was observed on a road cut on an east aspect above the Hurricane Ridge road.  On Saturday, riders remotely triggered a D1.5 (small-large) avalanche from the slope below. The avalanche had a 10" crown and propagated widely on a north-facing bowl near Victoria Overlook. The slide appeared to step down within weak snow to the stout 1/13 crust below.  

Leading up to this cycle on Thursday and Friday, professionals easily triggered 4-6" wind slabs in specific terrain features and shallow loose dry avalanches running on a stout crust. They also found recent snow and wind drifts over weak snow (facets) just above the stout 1/13 rain crust.  See an excellent observation here for more information.

2020-21 Forecast Schedule: Avalanche danger ratings will be issued for the Olympics every Friday through Sunday and during mid-week holidays. During the week when the Hurricane Ridge road is closed, forecast information will be updated daily to include expected conditions and relevant travel advice under the No Rating label.

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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