Bollettino valanghe

Mt Hood

Northwest Avalanche Center
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Pericolo valanghe

Tue
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
2 · Moderato
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Non aggiornato — questo bollettino è scaduto 4 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Dangerous conditions will develop as the day progresses. You can trigger an avalanche in areas where the wind has drifted new snow in fresh slabs. So keep your terrain simple and avoid steep slopes that appear wind loaded.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–2

    A few inches of new snow accompanied by strong to extreme NW winds will create a fresh crop of wind slabs. Winds will be cranking, so don’t be surprised if you find these slabs forming well below treeline, such as on open swaths or steep canyon walls. That being said, you’ll encounter the largest and most destructive slabs forming near and above treeline on leeward slopes, such as below cornices and east facing aspects. With strong wind speeds and intensifying snowfall, these slabs may grow large enough to bury you by the afternoon hours at these elevations.  I'd assume any drift you encounter will be reactive to your weight until proven otherwise. 

    Once you lose the wind, you lose the problem. However, that will be easier said than done, since the wind will likely be in your face at the trailhead. So use visual clues to help you identify slopes of concern. Keep an eye out for sharp cornices forming, fresh pillow-like slabs, or blowing snow. Take a big step back and avoid steep terrain if you notice shooting cracks or slabs sliding easily on smaller slopes.

    (1/17/2023)

    Shooting cracks - a red flag that should not be ignored.  Avoid wind loaded slopes if you notice signs like this. 

    Photo: Joe Dellaporta

Avalanche Discussion

Mt Hood will be joining the precipitation party starting Monday and with that, you’ll find dangerous conditions developing as the day progresses. Look for light to moderate snowfall and blustery conditions.  The biggest punch of precipitation will arrive Monday night and into Tuesday. 

Today I traveled into the Gunsight Ridge area to track possible weak surfaces on shaded aspects before heading into active weather. Due to high wind speeds, I didn't find much in the form of surface hoar or near-surface facets. That being said,  it doesn't mean it does not exist in other areas, so keep an eye out as new snow starts trickling in. What caught my eye was a sneaky layer of buried surface hoar about 17 inches below the snow surface. I haven't seen this layer in other areas on the mountain, but it's something worth highlighting if you travel along these ridges in the Bennett Pass or Pocket Creek areas. 

New snow will be falling on variable surfaces such as mosit snow,  thin sun crusts, or preserved settled power on shaded aspects. The big question mark will be how the new snow bonds with the old snow surface, especially on those more shaded aspects.  I did find surface hoar and near-surface facets in most areas below and near treeline in the Tilly Jane area on Thursday.  So as snow piles up, be on your game and check to see how sensitive the new snow is. 

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