Bulletin d’avalanche

Presidential Range

Mount Washington Avalanche Center
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Danger d’avalanche

Sat
Alpin
1 · Faible
Limite forestière
1 · Faible
Sous la limite
1 · Faible
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Périmé — ce bulletin a expiré 4 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Isolated areas of wind-drifted snow at middle elevations will be stubborn to trigger, except where warmed by the sun on south facing aspects. Watch for surface snow becoming wet as an indicator for instability. Crampons and an ice axe will be necessary in steep terrain to prevent a dangerous sliding fall.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely
    Taille
    1

    Small, shallow wind slabs can be found at middle elevations. These slabs will be stubborn to trigger and likely too small to bury a person, but large enough to initiate a fall in steep terrain. Warming on south aspects may decrease stability of the new wind slabs. You can easily spot the new drifted snow as bright white and smooth in appearance in contrast to the textured, icy surface of the refrozen old snow.

Avalanche Discussion

Yesterday, a March sun high in the sky worked to soften new and old snow on southern aspects. It was reported that a very thin wind slab on Sluice in Tuckerman Ravine warmed and was released by a skier. Higher air temperatures today may be enough to offset the reduced direct sun creating similar warming conditions as yesterday on southern aspects. Concerns of instability from warming are mostly limited to the recent wind slabs. 

Avalanche danger will increase after midnight tonight as a low pressure system moves into the Gulf of Maine and intensifies, bringing heavy snowfall to the forecast area. With around 1 inch of water (QPF), 12 inches or more new snow is possible with snowfall rates as high as 1 inch per hour. As wind shifts to the west and northwest in the morning, expect drifting snow to quickly build large wind slabs in east facing ravines. On east and southeast facing slopes, natural avalanches will be likely during the day tomorrow. Some uncertainty around temperatures may work to limit accumulating snow at lower elevations. Overall, temperatures will start on the warmer side and decrease throughout the day suggesting a “right side up” snowfall; however, increasing wind speeds may play a larger role in snowpack structure when the storm winds down on Sunday. 

Check the MWOBS Higher Summits Forecast this evening for updated information on this storm. 

Thanks to everyone for taking the time to submit observations of snow and avalanche conditions, both inside and outside our avalanche forecast area. Please keep them coming.

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

Régions couvertes