Lawinenlagebericht

East Slopes North

Northwest Avalanche Center
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Lawinengefahr

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

Kernpunkte

You're most likely to find and trigger a wind slab avalanche on lee slopes at upper elevations. You may see some wet rollerballs or small wet loose avalanches below treeline but they're unlikely to pose a hazard outside of extreme terrain features. Stormy conditions and increasing danger are expected on Sunday. 

Lawinenprobleme

  • Wind Slabs

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

    Shallow wind slabs may form just below ridgelines and below the bases of cliffs at upper elevations with moderate SW winds forecast tonight through Saturday.  Be on the lookout for new avalanches, blowing snow, wind-textured snow, and shooting cracks as you travel.  These clues will help you identify which steep slopes to steer clear of.  

    Prior to this storm cycle, cold temperatures may have formed a weak layer over a slick crust on shady slopes at upper elevations. While triggering a wind slab avalanche in the shallow new snow is the most likely outcome, it's possible that in isolated areas you could trigger a deeper avalanche down to this interface.  Use quick tests and dig just below the surface to look for this weak layer.

    (4/4/2023)

    Crown on NNE Aspect of Silver Star Mountain. This avalanche likely occurred due to wind loading. 

    Photo: Willie Webster

Avalanche Discussion

It's that time of year when snowpack information from the East North is sparse and injects more uncertainty into our forecast.  If you're out in any part of the zone on Saturday - please submit an observation and let us know what you see.  Stormy conditions and higher avalanche danger will likely develop on Sunday and Sunday night, so plan ahead if you're heading out for a multi-day trip. 

On Thursday night and Friday, areas east of Washington Pass (Harts Pass and Mazama) likely saw 2-5 inches of snow above 5000', with 2" or less near Washington Pass proper.  At the end of March, northerly aspects and upper elevations may have harbored weak snow surfaces. Snow that's slowly piled up in April may have bonded poorly to this older snow layer.  While we're well into April, the avalanche conditions and snowpack are closer to that which we typically see in mid to late winter. Much of the snowpack is nowhere near transitioning to typical spring melt-freeze conditions.

On Tuesday 4/4, Willie Webster went on an aerial tour of the zone and produced some great images of the current snow cover and recent avalanche activity. Notable were a couple of older avalanches including a very large natural slab avalanche on a NNE aspect of Silverstar Mtn and a natural glide avalanche on Hinkhouse Peak. See the photos below. On March 30th, Willie reported large debris piles on Harts Pass. The road was melting out quickly near Deadhorse Pt. He found a mix of sun crusts on the surface, though higher elevations looked to hold a cold, layered snowpack. 

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