Avalanche forecast

Mt Hood

Northwest Avalanche Center
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Avalanche danger

Tue
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Highlights

Strong winds and new snow will create a fresh crop of wind slabs on Monday.  Lookout for these slabs forming in unusual locations, such as further down slopes than usual due to high wind speeds.  Steer around steep slopes being actively wind loaded or show signs of recent loading, such as sharp-looking cornices or surfaces that appear wind textured.

Avalanche problems

  • Wind Slabs

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

    An additional 3-6 inches (.25 in swe) of new snow on strong to extreme WSW winds will create a fresh crop of wind slabs on lee terrain features.  You will specifically find these areas of wind drifted snow on slopes that face east, under cornices, and scattered through the alpine.  Due to the high winds, you may find these wind slabs forming lower down on slopes than usual.  These newly forming areas of wind drifted snow should be easy to spot and avoid.  Move around steep slopes being actively wind loaded or show signs of recent loading, such as wind textured snow or areas that appear smooth and rounded.  

    Anticipate where wind slabs are living by looking for where the snow is blowing.  Corncies are often great indicators of potentially wind loaded terrain beneath. 

    Photo: Joe Dellaporta

  • Persistent Slabs

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

    The likelihood of triggering an avalanche on the December 8th buried surface hoar has decreased, however, this layer can still be found across the zone. 

    Currently, this buried weak layer sits under 12-15 inches of snow.  Since its burial, we have been tracking its distribution across the terrain closely.  So far, the most sightings of this layer have been below and near treeline, specifically on open slopes with minimal canopy.  You can locate this layer by using snowpack tests and looking for a thin gray in the upper snowpack. 

    It's been over a week since our last known avalanche on this layer.  As of Sunday (12/18), my partner and I were easily able to still locate this thin gray line of surface hoar in the Vista Ridge area.  The good news is we noticed this surface hoar rounding and becoming harder and harder to fail in snowpack tests.  The bad news is we’re still receiving propagating test results when it does fail.  With that, consider sticking to smaller and lower consequence terrain until this weak layer is proven innocent.

     

    (12/15/2022)

    The layer of buried surface hoar was easily identifiable along the Tilly Jane Ski Trail.  Look for a thin gray line 12-15 inches below the snow surface. 

    SE aspect @ 5070 ft 

     

     

    Photo: Joe Dellaporta

Avalanche Discussion

This week will bring a steady trickle of precipitation with more arriving Tuesday and into Wednesday.  The main story until then will be the winds and cold temperatures.  Be sure to bundle up if you head out!

On Sunday my partner and I traveled into the Vista Ridge area.  We found a trace of new snow and variable surface conditions due to the wind.  Fortunately in this area, winds from the last 24 hours destroyed any newly developed surface hoar from the previous days.  Going into these next few days, continue to check how the new snow is bonding with the old snow surface. 

Thanks for all the great observations recently! Keep it up!

 

 

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