Bulletin d’avalanche

Presidential Range

Mount Washington Avalanche Center
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Danger d’avalanche

Fri
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
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Périmé — ce bulletin a expiré 5 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

New snow and westerly winds will increase the risk of avalanches on steep east facing terrain. Large avalanches are increasingly possible later in the day as newly formed slabs of wind drifted snow grow. Avoiding areas of snow that are rounded, hollow sounding and actively being loaded by new snow will decrease your exposure to today's avalanche problem.

Problèmes avalancheux

  • Wind Slabs

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

    As we gain precipitation this afternoon expect slabs of wind drifted snow to collect on east facing slopes. Westerly winds will shift and become erratic at times helping to load slopes and increase the avalanche danger. This evening it is likely that you could find dense and reactive slabs on steep slopes facing east. Slabs will grow quickly throughout the storm and could be capable of producing large avalanches.

Avalanche Discussion

This morning reports of light drizzle and snow are coming in from the Harvard Cabin snowplot at around 3000ft. As the precipitation turns to all snow this afternoon look for wind blown snow and growing slabs on the eastern slopes of the range. The winds will be nearly perfect for creating drifts of snow in the middle and upper elevation zones. 

Traveling in steep terrain after twilight could be risky as precipitation rates increase and the slabs of drifted snow grow thicker and more sensitive to triggering. Up to 10 inches of new snow could accumulate before midnight with drifted snow slabs exponentially deeper. Tonight you are likely to trigger a reactive slab that could become a large avalanche. 

Currently the snowpack is a mix of wind affected snow and old crusts that have gone through some decay. Areas of faceted snow lower in the snowpack are concerning as we gain new accumulations and more loading of snow from west winds. Although we have a relatively unconnected snowpack that is segmented by vegetation and rocks, destructive avalanches are possible today in the new snow.

Régions couvertes