Bulletin d’avalanche

Presidential Range

Mount Washington Avalanche Center
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Danger d’avalanche

Wed
Alpin
1 · Faible
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
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Périmé — ce bulletin a expiré 3 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Human-triggered avalanches are possible on areas of smooth wind-drifted snow on steep east-facing and south-facing slopes. To help avoid an avalanche, travel on hard, wind-scoured snow surfaces.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2

    Strong and extreme northwest winds have transported large volumes of snow to east-facing and south-facing slopes, creating new wind slabs. Expect these slabs to be firm and resistant to propagation. In small areas of slightly softer, wind-protected snow, triggering a hard slab avalanche is possible. In areas where the snow is firm, wind-sculpted, or scoured, triggering an avalanche is unlikely. 

    Areas of greatest concern may be lower in elevation than expected. Upper avalanche starting zones were scoured by extreme winds in most locations. Look for softer, smoother, more reactive snow in the middle portions of gullies, couloirs, and steep slopes to identify areas of greatest concern.

Avalanche Discussion

Over the past 36 hours, the higher summits have seen consistent wind speeds of over 70 mph with gusts well over 100 mph, which has redistributed recent storm snow from west and north-facing aspects to east and south-facing aspects. During this time, the Presidential Range went through a natural avalanche cycle with large avalanches observed in many locations. Check out this recent forecaster observation which outlines some of these. 

Though the extreme winds were the driving factor behind the recent avalanche cycle, they also have contributed to snowpack stability by creating strong and stiff wind slabs after many hours of intense wind speeds. In most areas, these slabs are strong enough to bridge significant weight across any instabilities underneath. However, in areas of softer snow, or invisible thin spots in the new slabs, it is still possible that the weight of a single person could trigger a large avalanche. 

Continue to make careful slope-specific assessments of avalanche terrain and practice thoughtful travel techniques to help mitigate this hazard today. This includes traveling through avalanche paths one-at-a-time, selecting routes that minimize overhead hazards, and traveling on hard, wind-affected snow surfaces. 

 

The Lion Head Summer Trail is CLOSED due to increased avalanche hazard. The Lion Head Winter Route is OPEN and the most direct route to the Mount Washington Summit from Pinkham Notch. 

OBSERVATIONS: Please consider submitting an observation of what you are seeing in your travels. Submitting an observation hones your skills, informs other users, and improves our forecasts.

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