Bollettino valanghe

Presidential Range

Mount Washington Avalanche Center
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Pericolo valanghe

Wed
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
Senza grado
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In sintesi

Continuous warm temperatures and incoming rain will increase the possibility of wet avalanches. The most likely place to encounter wet avalanches today is on easterly and southerly aspects, in areas where recent snow has collected and become saturated. Wet avalanches can be unpredictable. To avoid these avalanches, travel away from steep snow slopes with deep, soft snow.

Problemi valanghivi

  • Wet Slabs

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

    It will be possible to trigger a wet slab avalanche today on northeast through south aspects at middle and upper elevations. New snow from the weekend has been subjected to prolonged above-freezing temperatures over the past 24 hours and will see an additional input of rain during the day today. 

    As free water continues to move through this snow, wet slabs could occur if enough water lubricates the interface between new snow and the old, icy crust and naturally-triggered wet slab avalanches are not out of the question. These slabs are 1 - 2 feet thick and are located in sheltered, lee terrain where wind slabs formed on Saturday and Sunday.

  • Loose Wet

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

    Prolonged above-freezing temperatures and rain today will increase the potential for human-triggered and natural loose wet avalanches. The most likely places to encounter this problem will be on steep east-facing and south-facing slopes where new snow from the weekend is becoming saturated and weak. 

    Though these avalanches are generally small in size and slow moving, the heavy, wet snow can be surprisingly powerful and be enough to cause a loss of balance or a fall. Watch out for roller balls, small sluffs, and unsupportable surface snow as signs of this causing bigger avalanches in steep terrain.

Avalanche Discussion

New snow from the weekend, prolonged warming, and incoming rain are the main contributors to today’s avalanche problems. Yesterday, skiers in Tuckerman Ravine reported soft turns with varying moisture content based on aspect and elevation. Higher elevations and shadier aspects harbored moist but unsaturated snow. With a decrease in elevation and increase in sun exposure, snow became wet and saturated in many areas by the end of the day. 

Overnight at the ravine-level (4000-5000ft), temperatures did not fall below freezing. Temperatures on the Mt. Washington summit fell below freezing for a short time, but have returned to above freezing. As we move into today, this persistence of warm conditions and addition of up to 0.39 inches of rain will contribute to a loss of stability in the newer, unconsolidated snow from this weekend. It is important to keep in mind the unpredictability of wet avalanche problems if you choose to travel in avalanche terrain today. 

At high elevations above 5500ft, there is the potential for rain to transition to snow later in the day as temperatures drop. If this change happens earlier than forecast, there is an unlikely possibility for the formation of small wind slabs on lee aspects. Watch for the onset of snowfall and blowing snow to identify this problem.

Remember that significant melting has occurred over the last few days, bringing springtime objective hazards to the forefront. If you are in the mountains today be watching for: 

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.

  • The John Sherburne Ski Trail is closed at the third cut-over 3/4 down from the top.  Please cross over to the Tuckerman Ravine trail at the yellow rope and walk down the hiking trail.
  • The Harvard Cabin is closed for the season.

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

Regioni coperte