Bollettino valanghe

Presidential Range

Mount Washington Avalanche Center
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Pericolo valanghe

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

In sintesi

Significant new snow and wind have created dangerous avalanche conditions. You may encounter natural avalanches or find it easy to trigger an avalanche large enough to bury and kill you or others if travelling on steep east-facing and south-facing snow slopes.

Problemi valanghivi

  • Wind Slabs

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

    Wind and storm snow have formed new wind slabs in southerly and easterly aspects that could avalanche naturally and will be reactive to a human trigger. Slabs will vary in depth from 6 inches to 2 feet deep, large enough to bury and kill a person. It will be easy to find a thin spot in these slabs today, especially in gullies or couloirs that have been cross-loaded by wind and new snow.

Avalanche Discussion

Reported storm snow totals ranged from 6.9 inches at the Mount Washington Summit, 6 inches at Hermit Lake, and 13.4 inches at Grey Knob. Lighter wind speeds earlier in the day yesterday allowed for wind slab development with a hard-over-soft structure as wind speeds steadily increased yesterday afternoon and last night. We expect snow in avalanche start zones and other steep, wind-sheltered locations on east and south aspects to be reactive to human travel. With such high winds, this often happens lower down in the avalanche path than expected. With a shifting wind, like the one from yesterday to today, look out for variability in slab depth. Disrupting a thin, more sensitive area of a slab can be translated through the snowpack where the slab depth could be much deeper. 

In many areas, new snow has fallen on a slick old snow surface which may inhibit effective bonding of the two layers. In the case of an avalanche, this also creates a bed surface where it may be hard or impossible to arrest a fall, causing a victim to be subject to both the avalanche and the hazards of a long-sliding fall. 

Slowly but surely, the snow slopes across our avalanche terrain have grown more and more connected and this latest storm will certainly help that process along. This connectivity increases the potential for larger avalanches that span greater distances.  Expect this trend to continue as we move further into the avalanche season and more terrain options for skiing and climbing present themselves. Another important reminder as avalanche have the potential to become larger and larger is to be mindful of avalanche runout zones. Even popular viewing areas, like the floor of Tuckerman Ravine is avalanche terrain and gets routinely buried throughout the winter. 

The Lion Head Summer Trail is now closed for the season due to avalanche risk. The Lion Head Winter Route is open.

Please help us and your fellow skiers, riders, and climbers by submitting any pertinent or interesting observations to our website. 

Regioni coperte