Bollettino valanghe

Mt Hood

Northwest Avalanche Center
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Pericolo valanghe

Fri
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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Non aggiornato — questo bollettino è scaduto 5 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Continued light snowfall and strong winds will maintain concern for human-triggered avalanches in wind-drifted snow at upper elevations. Look and feel for changes in snow surface texture and hardness to help you identify steep wind-loaded slopes you want to avoid.

Problemi valanghivi

  • Wind Slabs

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

    Avalanches in wind drifted snow will become larger and easier to trigger as you gain elevation. These avalanches will be most likely to fail within new and wind drifted snow and will be most sensitive on east through north aspects above 6000ft in terrain steeper than 35 degrees. Steer around large open alpine slopes below cornices, cliff bands, and ridgelines with evidence of fresh wind loading. Pay attention as you transition into wind-affected terrain. You'll find windward slopes scoured to the old icy surface, and leeward slopes drifted in with firm, chalky snow. Use these visual clues along with blowing snow as the easiest tools to identify slopes with fresh wind slabs. If you experience cracking or see recent avalanches, choose lower-angled terrain sheltered from the wind.

    (1/31/2022) Westerly winds blowing snow at ridgetop, scouring down to the hard, icy old snow surface and loading a NE aspect. Photo: Andrew Kiefer

Avalanche Discussion

Since January 30, incremental snowfall brought 4-day storm totals to around 12in above 5000ft. The recent snow is heavily affected by wind but settling quickly. Many upper elevation slopes are scoured down to the old, icy snow surface (Late January Crust). Hard wind slabs formed in leeward areas, but appear well bonded to the old crust and are stubborn or unreactive to triggers. In areas sheltered from the wind, small dry loose sluffs are possible to trigger, but have not been large enough to pose much of a hazard to backcountry travelers. Ongoing light snowfall, gusty winds, and poor visibility limited recent observations above treeline. The slick icy old snow surface is exposed or shallowly buried in many areas, especially in windward terrain (S and W aspects), and below treeline where less snow accumulated. The new snow provided a much-needed refresh though, and riding quality improved.

Despite the new snow, slick, icy, and hazardous travel conditions still exist where the old snow surface is exposed. Icy conditions led to numerous falls and multiple rescues on the upper mountain over the past week, and several snowmobilers lost control on the slick surfaces at Skyline and Frog Lake SnoParks with accidents and severe injuries reported. Keep your guard up - snow surfaces are variable out there and can change rapidly with aspect and elevation.  

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