Lawinenlagebericht

West Slopes North

Northwest Avalanche Center
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Lawinengefahr

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

Wet snow avalanche danger will linger into Wednesday, although a cooling trend starts early in the morning. Stay off steep slopes, and avoid flatter areas beneath these slopes while the snopwack remains wet and sloppy. Snowfall and wind could develop shallow but reactive drifts of snow at upper elevations in the afternoon. 

Lawinenprobleme

  • Loose Wet

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Likely
    Größe
    1–2

    NWAC Forecaster Lee Lazarra saw several wet loose avalanches which occurred naturally sometime Monday evening through Tuesday morning in the Baker backcountry. He was able to easily trigger avalanches on steep slopes that hadn’t already slid (video). Expect another day where you can trigger wet loose avalanches with the soggy conditions. Temperatures will cool on Wednesday so expect the most reactivity earlier in the day. Midday, rain in the near treeline vicinity might continue our elevated concerns for wet loose avalanches as the rain transitions to wet snow. Avalanches may grow larger and more destructive as rain falls. 

    When snow remains wet and you can still sink down in it, you can probably still trigger wet loose avalanches on steep slopes. Travel in these areas and runouts beneath large avalanche paths is not recommended. With this much warming and water in the snowpack, we might also encounter wet slab avalanches, which are much less predictable than wet loose avalanches. This is another reason to steer clear of large steep slopes on Wednesday. Wet avalanche danger may decrease in the afternoon as temperatures continue cooling.

  • Wind Slabs

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

    Snowflakes may begin falling late morning at upper elevations, which will continue creeping further downhill as the day progresses. Moderate to strong winds at upper elevations will likely redistribute the new snow into shallow wind slabs, which could react to a human trigger. If you venture into upper elevatioms, assess the depths of the new snow and pay attention to how well the new layer sticks to the underlying wet layer. If you see shooting cracks or can easily break small pockets, consider the potential for triggering an avalanche on a steep slope, and consequences if you are caught in it. 

    You might be able to trigger small wind slabs Wednesday afternoon. This is an example of a small pocket releasing, an indicator that you might be able to find others that are larger than this one around.

    Photo: Adam Ü

  • Deep Persistent Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    3

    The unseasonable warmth and added water on the snowpack could slightly elevate the chances of a very large slab avalanche occurring. We previously saw avalanches on this deep persistent layer a week ago, which most likely occurred on the March 8 facet layer, now buried 3-5+ feet deep. We are remaining concerned about this layer for now, with elevated chances of a smaller avalanche or cornice fall as a potential trigger, and until we find the layer gaining more strength. 

    This isn’t really a “manageable” avalanche problem that can be figured out. You are either in the terrain where one of these large, unsurvivable avalanches could occur, or you are not. If you choose to travel in these areas you are simply accepting a slightly higher risk of triggering or being exposed to a very large avalanche.

Avalanche Discussion

There is uncertainty about how the snowpack will evolve as the weather changes. Wet snow could stay reactive for a while, or avalanches could become less frequent early in the day. Stay alert and pay close attention to changing conditions in the backcountry as you travel. Don’t ignore obvious signs like recent nearby avalanches. 

Freezing levels drop throughout the day, and we could see 3-5 inches of snow above 5000ft by evening. This snow will probably have a moist nature to it, especially at mid elevations, and it will insulate the wet snow beneath it. Especially in the NTL it could behave more like wet snow, rollerballing, and possibly sliding easily on the saturated layer beneath it. Despite the fresh snow coating, avalanches couldy still run deeper than the new snow layer, especially if a human trigger is involved.

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