Bollettino valanghe

Mt Hood

Northwest Avalanche Center
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Pericolo valanghe

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

In sintesi

New snow and wind will combine to create reactive pockets of wind drifted snow on leeward slopes. Consider sticking to more sheltered slopes and avoiding snow that appears rounded and wind stiffened.

Problemi valanghivi

  • Wind Slabs

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

    Despite the switch to spring, Thursday should provide a good dose of precipitation and strong west winds. So as a result, look for wind slabs to be forming on typical leeward features. As new snow stacks up, slabs will grow in size and distribution across the terrain, and may just be large enough to bury you above treeline by the afternoon hours. These wind drifted slabs may be easily triggered since they’ll be forming on crust and possibly graupel that fell on Wednesday. 

    As you move through the mountains, look for and avoid rounded or pillow-like slabs of snow. You’ll typically find these slabs forming on the downwind side of ridges, below cornices, and under cliffs. You can use visual clues such as blowing snow or sharp cornices forming to help you identify slopes of concern. Shooting cracks under your skis/split/sled/feet are direct signs telling you that you found an unstable slab of drifted snow. Sticking to more sheltered slopes out of the wind zone or traveling on scoured surfaces is a good way to reduce your exposure to this problem. 

    (1/17/2023)

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

    Photo: Joe Dellaporta

Avalanche Discussion

Back to winter!  Mt Hood is forecast to receive over a half inch of water with dropping snow levels and strong wind speeds. The question mark will be how this new snow bonds to the preexisting snow surfaces. From what we know right now, we have a thin crust capping the snowpack and now possibly graupel resting on the snow surface in many locations. So as you travel use small test slopes or hand pits to gauge how easily the new snow fails. While unlikely, the sun could poke out for brief periods of time, especially on the eastern edges of the zone. So keep an eye out for warming snow surfaces on steep solars. This likely won’t be much of a problem, but worth mentioning if you find yourself traveling on or under solar aspects. 

Wednesday was very much a transition day for the Mt Hood zone. Observers reported finding a widespread thin heat crust that extends to 9000 ft and increasing cloud cover. Later in the day the Meadows patrol reported graupel showers before switching over to snow/rain. 

 

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