Bollettino valanghe

Presidential Range

Mount Washington Avalanche Center
Vedi sulla mappa

Pericolo valanghe

Mon
Alta quota
1 · Debole
Limite del bosco
1 · Debole
Sotto il limite
Senza grado
Open full map
Non aggiornato — questo bollettino è scaduto 4 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Rain transitioning to snow this afternoon will change the avalanche problems throughout the day. Wet snow will begin to refreeze as dry snow starts to collect on eastern aspects in the higher elevations. Firm icy surfaces will have a coating of fresh wind deposited snow later this evening that could potentially create small human triggered avalanches.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely
    Dimensione
    1–1.5

    As the weather changes this afternoon from rain to snow, drifted slabs on the eastern aspects will grow in size. 1 to 3 inches of snow is expected to fall with moderate west winds that will shift northwest as the storm progresses. Initially the surface snow will be wet and sticky and new snow will adhere to the slopes well. As we get closer to the evening hours, slabs will build thicker and will be more likely to fail from a human trigger. Increased winds and colder temperatures will contribute to the avalanche problem by loading drier snow on slick refrozen surfaces.

  • Loose Wet

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

    The prolonged Wet Loose avalanche problem will lose its sensitivity slowly, as afternoon temperatures drop below freezing. Saturated loose snow will be a problem for travelers during the morning hours but will refreeze in the afternoon becoming a serious sliding fall hazard. At this point, rain has percolated through most of the dry snow left in the snowpack. Expect subsurface snow to act more like a single homogenous layer after the lock-up from cold temperatures.

Avalanche Discussion

Warm air and rain will be pushed out of the mountains by a colder low pressure system this afternoon, dropping temperatures below freezing in the upper elevations. As rain changes to snow expect surfaces to refreeze and become very icy on all aspects. Water that has infiltrated the snowpack has wetted most of the dry snow, leaving us with a new bed-surface. Timing will be critical for understanding the transition of contrasting avalanche problems throughout the day, as wet avalanche problems change back to dry avalanche problems.

Yesterday during the annual Inferno Pentathlon, rain and thick cloud cover dominated the skies. Skiers endured wet loose snow conditions from the ravine to the bottom of the Sherburne Ski Trail. Receding snow in the lower elevation zone has neutralized the potential for avalanches here, therefore below treeline slopes have been taken off the hazard rating for the time being. Thin and rock-peppered conditions exist on the lower extent of the Sherburne and caution is advised.

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

Regioni coperte