Bollettino valanghe

Mt Hood

Northwest Avalanche Center
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Pericolo valanghe

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2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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In sintesi

You’ll have to manage both dry and wet snow avalanche problems depending on your elevation and timing. Triggering small wet avalanches will be possible during periods of rain or whenever you find yourself sinking past your ankles in wet punchy snow. However, as you climb higher above the snow line, shift your focus to newly forming wind slabs and slick, icy surfaces. 

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–1.5

    Wind slabs will continue to grow as new snow falls above the rain/snow line. While these slabs should remain small, they could trigger easily where they form over a slick rain crust. Keep in mind that a small avalanche on a slick bed surface could result in a longer, more consequential sliding fall. 

    Use visual clues like blowing snow and textured, rippled surfaces to help you identify wind loaded features. You’ll typically find these slabs for these slabs on the leeside of ridges & canyons, below cornices, or on the beak-over of steep alpine slopes. You can use small test slopes or hand pits to gauge how reactive these slabs are. Cracks shooting out from under your feet or skis are obvious signs that you may have found an unstable slab.

    (1/22/2024)

    Default to less exposed terrain if you notice active drifitng. 

    Photo: Joe Dellaporta

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1

    With increasing freezing levels and more rain-on-snow at middle and lower elevations, wet loose avalanches will stay on the menu for Sunday. The snowpack has been through a lot by now, so I suspect these will be more of an issue at middle elevations that pick up a few inches of snow before the changeover to rain. These wet loose will likely stay small and only entrain new snow, but don’t be caught off guard in steep, consequential terrain. Move to lower-angle or firmer slopes if you notice rollerballs shedding or if you sink past your boot top in wet, sloppy snow.

    (12/28/2023)

    Rollerballs or rain on snow are good reasons to simplify your terrain choices. 

    Photo: Lee Lazzarra

Avalanche Discussion

You’ll have to balance dry and wet snow avalanche problems on Sunday as freezing levels can’t make up their mind. The Mt.Hood zone will be in for a brief warm-up as snow levels climb up to 6500 ft during the afternoon hours. This will likely result in an unfortunate change-over to rain at most middle and lower elevations with snow continuing to fall somewhere above 6500 ft. 

The lower and mid-elevation snowpack is well versed in handling liquid water. We suspect any new snow will bond well and any additional rain shouldn’t be much of an issue outside of small wet loose avalanches involving recent accumulations. Upper elevations remain firm and will require the proper gear (cramons, ice axe, and skill) to travel over steep terrain.  

The 12/17 rain event brought nearly 2 inches of rain to upper mountain elevations. This led to a widespread natural avalanche cycle with numerous D2 to D3-sized avalanches in the canyons around Mt. Hood. This rain event was also responsible for creating rain runnels along many mid and lower-elevation slopes and a slick, widespread rain crust in upper mountain terrain.

If you get out, we could use the observation. Submit an observation here.

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