Avalanche forecast

Presidential Range

Mount Washington Avalanche Center
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Avalanche danger

Sat
Alpine
2 · Moderate
Treeline
3 · Considerable
Below
1 · Low
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Highlights

Large avalanches are possible above 3000 feet today as heavy rainfall saturates the snowpack at all elevations. Stick to lower-angle terrain and avoid gullies and other terrain traps where even a small slide can have serious consequences.

Avalanche problems

  • Wet Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2

    What and where is it: Wet slab avalanches are the primary concern during daylight hours as rain and warming temperatures affect the snowpack. While the snowpack is generally stable, isolated areas on northeast, east and southeast aspects still hold a buried weak layer (OBS1, OBS2) that could become more reactive as water percolates into the snowpack.

    How can you recognize it: A wet snowpack is the obvious red flag. Rain on snow, rapidly increasing boot penetration, and heavy, saturated snow all indicate deteriorating stability. In addition to wet slabs, watch for loose wet avalanches in areas where unconsolidated snow lacks structure. This is most likely where deep, pooled graupel was observed yesterday, as these deposits can lose cohesion quickly once water is introduced. Determining where buried weak layers exist will be challenging or impossible during periods of heavy rain, so treat any steep slope with wet snow as suspect.

    How can you manage it: Conservative decision-making will provide important margins of safety today. Avoid steep terrain where the snow is wet or becoming wet, and stay out from under avalanche paths as rain and warming intensify. Stick to lower-angle terrain and avoid gullies and other terrain traps where even a small slide can have serious consequences.

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2

    What and where is it: A developing wind slab problem is expected after dark as precipitation changes back to snow and strong west winds increase. New snow will initially fall with a “right-side-up” structure as temperatures cool, but rapid loading and wind transport will quickly redistribute this snow into cohesive slabs on lee aspects. The primary areas of concern will be north through south-facing terrain at middle and upper elevations. How can you recognize it: Look for fresh, smooth, wind drifted snow forming overnight, especially in terrain sheltered from the wind. Increasing blowing and drifting snow, and snow that feels hollow or slabby underfoot are key signs that wind slabs are developing. This will be difficult to assess after dark and during periods of strong wind and snowfall, making visual cues limited.How can you manage it: Evaluate snow carefully in lee terrain where slabs are actively forming overnight and tomorrow. Favor wind exposed, textured surfaces and be cautious when transitioning into sheltered terrain. 

Avalanche Discussion

Wet snow avalanche problems are inherently difficult to predict and manage. As rain and above freezing temperatures move into the mountains, liquid water will percolate into the snowpack in uneven and hard-to-anticipate ways, while the added weight of the rain places additional stress on existing layers. Although the snowpack is generally stable, previously unreactive weak layers can become reactive once they are wetted and loaded. Wet slab avalanches often provide few reliable warning signs before releasing and can be highly destructive due to the weight of the snow, making it challenging to assess where and when instability may develop. Given this uncertainty, conservative decision making is especially important today. This is not an avalanche problem to outsmart.

Looking ahead to tomorrow, colder air and strong west to northwest winds will bring a rapid refreeze and a transition back to a dry snow, with developing wind slabs becoming the primary concern in lee terrain. Until the snowpack has time to adjust to these rapid changes, favor lower-angle terrain, and be especially cautious around recently drifted snow.

Regions covered