Bollettino valanghe

Presidential Range

Mount Washington Avalanche Center
Vedi sulla mappa

Pericolo valanghe

Tue
Alta quota
2 · Moderato
Limite del bosco
3 · Marcato
Sotto il limite
1 · Debole
Open full map
Non aggiornato — questo bollettino è scaduto 8 months ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

It will be easy to trigger small avalanches in new, wind-drifted snow on east-facing slopes above 3000 feet in elevation. As winds continue to increase, avalanches could also occur naturally. Careful snowpack evaluation and cautious route finding is critical if traveling in avalanche terrain today.

Problemi valanghivi

  • Wind Slabs

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

    What and where is it: New wind slabs formed from 4-6 inches of very light density snow may avalanche easily from the weight of a person and have the potential to avalanche naturally. The most likely place to find a sensitive wind slab is between 3000 and 5000 feet on east-facing slopes and in terrain features that provide protection from the wind. 

    How can you recognize it: Slabs are likely to be soft and feel completely different than the firm, old snow underneath. Watch out for new slabs that have a poor strong-over-weak structure, shooting cracks and collapsing underneath your feet, and areas where you're sinking into the new snow past the tops of your boots. 

    How can you manage it: Carefully evaluate the snowpack while moving through the terrain to understand the size and sensitivity of new wind slabs. Minimize your time spent underneath steep snow slopes due to the possibility of naturally occurring avalanches. Understand that wind slab size and sensitivity could be highly variable based on aspect and elevation and factor this into your travel plan.

Avalanche Discussion

Old wind slabs that were talked about in the forecast yesterday are mostly firm, supportable and well bonded with the rest of the snowpack. The primary concern today is the formation of soft, reactive wind slabs that are now sitting on top of that old snow surface. 

4-6 inches of very light density snow, a progressively increasing wind speed, and a firm old snow surface, are a recipe for reactive wind slab avalanches today. While these avalanches are not expected to be large, they could be incredibly sensitive and create more than enough force to sweep a person off balance and potentially have enough snow to bury a person. Observations from yesterday showed significant amounts of new snow available for transport in upper elevation terrain, and the beginning of the wind-loading process as winds began to increase yesterday afternoon. Given the uncertainty around the size of new wind slabs, it is critical to stay vigilant and observant if you choose to travel in avalanche terrain today. Dig into the snow to understand how sensitive new wind slabs are and watch for red-flag signs of instability including long shooting cracks under your feet, collapsing of the new snow, recent avalanche activity, and plumes of new snow being moved by the wind. OBSERVATIONS: Please consider submitting an observation on our website or in the new Avy phone app of what you are seeing in your travels. Submitting an observation hones your skills, informs other users, and improves our forecasts.

Regioni coperte