Lawinenlagebericht

Lawinenlagebericht

Payette Avalanche Center
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Lawinengefahr

Hochgebirge
2 · Mässig
Waldgrenze
2 · Mässig
Unterhalb
2 · Mässig
Veraltet — dieser Lagebericht ist 3 years ago abgelaufen. Du siehst vergangene Verhältnisse, nicht den aktuellen Bericht.

Kernpunkte

South Wind and new snow today will form fresh wind slabs in leeward terrain above 7,000 feet.

Triggering a Persistent slab avalanche 2 feet deep is still possible across all aspects and elevations. These avalanches could step down to older, weak snow near the ground creating a very large avalanche (D2-D3).  Sustained warm temperatures and rain keep wet loose avalanches possible below 7,000'.  

Lawinenprobleme

  • Persistent Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1.5–2.5

    2-4 feet of new snow last week fell on a variety of buried weak layers. This recent snow formed a slab about 2 feet thick overlying persistent weak layers that were buried in early January. Between solar and shaded aspects, you'll find a layer of buried surface hoar/near surface facets OR facets sandwiched between two melt-freeze crusts. Both of these weak layers are about 2 feet down and are slowly strengthening.

    Unfortunately, this persistent slab problem is widespread across all aspects and elevations and lies in the upper snowpack within the depth for riders and sliders to both trigger. 

  • Deep Persistent Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Unlikely
    Größe
    2–3

    Triggering an avalanche on deep persistent weak layers from November is unlikely. The poor snowpack structure continues to raise alarm, especially with continued weight being added to the snowpack. Warm temperatures and rain/snow are adding weight to the slab and stressing buried weak layers. You are most likely to trigger a large avalanche within old snow near the ground in steep, rocky terrain where the snowpack is shallow. You're not likely to see or hear any signs of instability on this weak layer buried over 3 feet deep. Although, if you dig into the snowpack, you'll most likely find evidence of it. The biggest concern with this deep persistent slab is triggering a persistent slab within the upper snowpack and stepping down deeper to weak snow near the ground. These avalanches would be large enough to destroy a small house, such as the one that occurred naturally earlier this week in Deer Creek.

  • Wind Slabs

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

    South winds and new snow will start to form wind slabs through today and through tomorrow in exposed and leeward terrain. Watch for signs of wind loading and red flags like cracking. Small wind slab avalanches can have big consequences in the wrong terrain.

Avalanche Discussion

 Lower elevations have not seen a freeze. Sustained warm temperatures and rain keep small wet loose avalanches possible below 7,000'.  The upper snowpack still holds the potential to fail on a layer of buried surface hoar or a combo of crusts and facets depending on where you are. This problem is persisting yet showing some strength in our tests. The complexity in dealing with this ongoing problem is variable across our advisory area: some places have slid already, or the weak layers have the right exposure to the sun and or wind and are not a problem, and in other locations, the weak layers are still weak enough to send a fracture a distance.

Utilizing conservative travel protocols in case of the worst-case scenario could be the best action if not just abstaining from big northern exposed lines that have consequences like being dragged over cliffs, through rocks, and or logs. Overall snowpack coverage remains thin to minimal which drives basic conservative travel alone.

We submitted and received some good observations yesterday with good photos. Get your name in the hat to win some gear in our FPAC monthly drawing when you submit an observation. Submitting an observation improves your skills, informs other users, and benefits avalanche forecasts. Simple photos highlighting conditions are very helpful.

Did you know there several avalanche classes this month specifically for motorized users? Check out our classes and events page to learn more.