Avalanche forecast

Mt Hood

Northwest Avalanche Center
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Avalanche danger

Mon
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
3 · Considerable
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Out of date — this forecast expired 4 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Sunday will not be the day to let your guard down. Triggering a large avalanche remains likely on steep, open slopes above 35 degrees.  Let the snowpack heal by traveling on lower-angle terrain and limiting your overhead exposure.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2.5

    Moderate wind speeds will continue to drift new snow and build fresh wind slabs that will be 2-4 ft deep.  You’ll likely find these wind slabs in different elevation bands, but you’ll find the largest slabs on the lee sides of ridges, below cornices, and above treeline.  On Sunday avoid slopes being actively wind loaded or show signs of recent loading.  Look for visual clues such as textured snow surfaces that look rounded or rippled from the wind.  These slabs of wind drifted snow may be especially reactive if they sit on top of a buried layer of surface hoar or near-surface facets. 

    (12/9/2022)

    Wind loaded slopes will often exist directly under freshly formed cornices like this. 

    Pea Gravel Ridge, ~5900ft

    Photo: Mitchell Barton

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2

    After 12 + inches of new snow (1+ in swe) in the last 24 hrs, slabs will continue to be reactive, especially in areas where weak surface snow was buried.  Suspect that any steep, open slope may harbor this surface hoar, so using conservative terrain selection will be critical.  Use hand pits or test slopes to evaluate how the new snow bonds to the old surface.  

     

    Using quick hand pits is a great way to see how the new snow is bonding  to the old snow surface.  With storm slabs look for hard over soft layering. 

    Photo: Tre Trofi 

Avalanche Discussion

On Saturday the Mt. Hood Meadows Pro Patrol triggered large avalanches with explosives.  They observed avalanches releasing sympathetically and failing 1-3 ft deep on a layer of preserved stellars and surface hoar.  Check out the forecast photos for more details.  

Another observor in the Bennett Pass area unintentionally triggered a D1.5 soft slab with their snowbike.  They reported crown depths ranging 12-18 inches deep and failing on that new/old snow interface. 

On Friday before the large bulk of precipitation arrived, my partner and I went hunting for buried surface hoar and we were able to locate it in most areas we dug at lower and mid elevations ( full observation here). 

All of this recent information illustrates that we have a complex snowpack.  Until we know more about the distribution of this recently buried  weak layer, take a large step back and avoid steep slopes.  

If you get out into the backcountry,  please submit an observation on our public observation platform!  These observations play an integral role in producing a quality avalanche forecast, but also help the greater backcountry community.

Regions covered