Avalanche forecast

Presidential Range

Mount Washington Avalanche Center
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Avalanche danger

Sun
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
1 · Low
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Highlights

You could trigger a large avalanche in steep, wind-loaded terrain. Avalanches from new snow and winds have the potential to ‘step down’ into deeper weak layers in the snowpack and create a much larger, more destructive avalanche. To reduce your risk, steer clear of obvious drifts and slopes where wind drifted snow has collected and minimize time spent beneath avalanche paths.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2.5

    What and where is it: Winds over the last 48 hours have built hard and soft wind slabs on easterly aspects from 5–6 inches of recent snow, and today’s additional 2–4 inches will continue to add to them. With westerly winds transporting new snow, expect fresh slabs to form and existing slabs to grow in wind-loaded and cross-loaded features, with 2–3 foot thick slabs possible. In some locations, these slabs sit on the January 10 melt-freeze crust, a smooth bed surface that can promote wider propagation.While these slabs can be found in many locations, we are calling out the Summer Lion Head Trail as an area of special concern after forecasters found a large, sensitive wind slab there yesterday. Travel on the Summer Lion Head Trail is not recommended today due to dangerous avalanche conditions.How can you recognize it: Visibility may be poor, making instability clues harder to spot. Look for smooth, pillowy drifts below ridgelines and in cross-loaded gullies. Blowing snow is a red flag for active loading. Use boot penetration and a ski pole to gauge slab thickness, and watch for shooting cracks - especially in deeper drifts on steep slopes. 

    How can you manage it: Assume wind-loaded easterly terrain is dangerous today, especially where you find connected drifts deeper than your boot tops. Use quick hand shears or simple column tests to check how well the slab is bonded to the bed surface. Favor firm, scoured surfaces and limit your time below avalanche paths as loading continues.

Avalanche Discussion

The forecast area remains in a dynamic weather pattern, and avalanche conditions are changing quickly. Yesterday, MWAC forecasters and field observers found that strong northwest winds used the recent 5–6 inches of new snow to build reactive wind slabs on easterly aspects around 4,000 feet. In protected and semi-protected terrain features, these slabs were 2-3 feet thick and reactive to human triggers. It is important to note that nearly all observations came from protected and semi-protected locations due to the extreme cold and wind. However, given the sustained transport observed throughout the day, it is reasonable to expect similar slabs were also constructed in slightly more exposed areas, such as the mid-track of larger gullies at comparable elevations and aspects, with slab size and reactivity varying in proportion to the degree of wind exposure. Today, another 2-4 inches of light density snow is possible through the day. With westerly winds, this new snow will continue to be transported and form wind slabs on easterly aspects. The loading rate should be slower than yesterday, but the pattern remains the same. While some of yesterday’s slabs may have become less reactive in wind-exposed terrain due to continued strong winds, either being scoured away or compacted into harder slabs, avalanche conditions remain elevated. New slabs will continue to build on top of the current slabs, and in many places these stacked slabs are sitting on the January 10 melt-freeze crust, a firm layer that can act as an efficient bed surface.OBSERVATIONS: Please consider submitting an observation on our website or in the new Avy phone app of what you are seeing in your travels. Submitting an observation hones your skills, informs other users, and improves our forecasts. 

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