Bollettino valanghe

Presidential Range

Mount Washington Avalanche Center
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Pericolo valanghe

Sun
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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Non aggiornato — questo bollettino è scaduto 6 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Heightened avalanche conditions may exist in lee areas near the tops of gullies, beneath steep terrain features, and in any area where wind blown snow has accumulated. Good visibility today with moderating temperatures should allow for careful observations of pillows of drifted snow which may be hollow sounding. Natural avalanches are unlikely today but human-triggered wind slab avalanches remain a concern. MODERATE avalanche danger exists in wind loaded areas. Evaluate snow carefully, expose only one person at a time to the avalanche hazard and carry the minimum safety equipment, which includes an avalanche transceiver, shovel, and probe.

Problemi valanghivi

  • Wind Slabs

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

    Light but steady snowfall earlier in the week deposited 4-5” new snow in the alpine. Winds have been more moderate than usual this week while cold temperatures have been in place to slow stabilization. These factors combined with the porcelain-like bonding surface of the 157 mph surface from last Saturday's wind event creates some uncertainty around the sensitivity, size, and distribution of wind slabs.

Avalanche Discussion

It is possible that the wind slabs in our terrain are stubborn and exist only in isolated areas but frigid temperatures (and vaccine induced malaise) yesterday prevented field observations. If you are venturing into avalanche terrain today, use a moderate danger rating as your starting point, and perhaps you’ll discover conditions that more accurately fit the low danger rating. While human-triggered avalanches are unlikely under a low danger rating, they are never impossible so use safe travel techniques as you assess for the hazards, which also include sliding falls on the hard, old wind slab (aka “the 157 surface”). Another snowpack issue to keep in the back of your mind is the 1/16 melt/freeze crust that remains beneath our relatively paltry snowpack. Frigid temperatures create the kind of vapor pressure differentials that degrade ice crusts and grow weak layers of facets. While our snowpack typically varies greatly in spatially in thickness due to wind transport, don’t ignore this process entirely. Crusts can change over time and as they weaken they can cause avalanches as well as contribute more snow crystals to wind loading events. 

Stay vigilant out there and look out for each other. 

Your avalanche, snowpack, or weather observations are extremely valuable to the forecasters at MWAC. Help create a more accurate avalanche forecast by submitting your observations here. 

Listen to the weekly MWAC Outreach Podcast provided by Ski The Whites. Discussions include snowpack information, weekend outlook, and general avalanche related info. 

Thursday, February 4 @ 7PM - Avalanche Awareness with Al Mandel.Al Mandell of Acadia Mountain Guides joins us to chat live about Avalanche Awareness.  We hope you join us!

The Harvard Cabin is open for camping only with no entry allowed inside the cabin.

Please Remember:

  • Safe travel in avalanche terrain requires training and experience. This forecast is just one tool to help you make your own decisions in avalanche terrain. You control your own risk by choosing where, when, and how you travel.
  • Avalanche danger may change when actual weather differs from the higher summits forecast.

For more information contact the US Forest Service Snow Rangers, AMC visitor services staff at the Pinkham Notch Visitor Center, or the caretakers at Hermit Lake Shelters or seasonally at the Harvard Cabin (generally December 1 through March 31). The Mount Washington Ski Patrol is also available on spring weekends.

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