Lawinenlagebericht

West Slopes Central

Northwest Avalanche Center
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Lawinengefahr

Sun
Hochgebirge
3 · Erheblich
Waldgrenze
3 · Erheblich
Unterhalb
2 · Mässig
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Kernpunkte

A marked increase in avalanche danger will arrive with the weekend, as 6-10 inches of snow will fall Friday night at mid to upper elevations accompanied by strong winds.  Steer around steep slopes where new storm snow deposits are greater than 6 inches, as human triggered avalanches are likely. As you make your way above treeline, wind will have influenced the snow and areas with thicker, wind-affected deposits could produce larger and more reactive avalanches. 

Lawinenprobleme

  • Storm Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Likely
    Größe
    1–1.5

    A surprising uptick in avalanche activity means that Saturday is a day to stay on your toes in the backcountry. You can expect storm slabs to avalanche with a human trigger in steep areas where more than 6 inches of snow is present. Above treeline, wind will probably have affected the new snow layer, and thicker slabs which developed with wind loading will probably be more reactive to a human trigger. Wind-affected surfaces may be difficult to identify, as a few inches of snow will continue to fall throughout the day and may sneakily hide the thicker slabs. 

    Always pay attention to signs like long, shooting cracks traveling out from your feet or sled, whumphs, and recent avalanches. These are some of your best indicators to stick to lower-angle terrain. Small test slopes are good locations to check for instabilities in the top foot or so of snow, like what we'll be seeing on Saturday. Hand pits could also help you identify if the new slab slides easily on the old snow surface. Even if you're checking the snow with these tests, Saturday is probably a day to avoid heading out onto steep slopes, and sticking to terrain less than 30 degrees. 

    Storm slabs could surprise you on unsuspecting slopes, like this old photo.  Photo: Public Obs

  • Loose Wet

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1

    A freezing level rising to 4500ft in the afternoon means we could see some small wet loose avalanches at lower elevations. Activity could just be rollerballs, or enough snow could get entrained to produce small avalanches. Snowline for the majority of the storm is resting at about 3000ft before freezing levels start increasing, so the lower elevations of where we see new snow is where you can expect any wet loose avalanche activity to occur. If you notice rollerballs or small wet loose slides coming down, give nearby steep locations a wider berth. Wet avalanche activity will likely remain limited to the newly fallen snow. 

    You may see rollerballs like these running from steep areas on Saturday. These are a good early indication that the snow surface is destabilizing and wet loose avalanches are possible.

    Photo: Robin Pendery

Avalanche Discussion

We discovered weak snow surfaces that formed during last weekend's cold snap in neighboring zones, which we expect also exists in this zone. As a hearty new load of snow falls, avalanches may occur easier than expected on this old snow layer. We're not quite sure exactly how reactive this new, larger addition of snow will be, but it's a good idea to start your day conservatively before even considering stepping out into steeper areas.  

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