Avalanche forecast

Presidential Range

Mount Washington Avalanche Center
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Avalanche danger

Tue
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Highlights

On steep, east-facing and south-facing snow slopes, it is possible for a person to trigger a large avalanche today. Areas with heightened avalanche danger will likely have soft or smooth snow drifts where terrain features have protected the snow from the wind. Traveling on hard, wind-scoured snow surfaces is the easiest way to avoid the avalanche problem today.

Avalanche problems

  • Wind Slabs

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

    Large wind slabs up to D2.5 in size with depths of up to 3 feet will be possible for a person to trigger today on lee terrain and sheltered terrain features. Firm slabs may give a false indication of stability because of the potential for weak snow to exist underneath a firm, supportable slab. It will be important to assess the stability of a slab down to the old, icy crust layers before committing to traveling on a slope. Approach soft or smooth snow with a critical eye and caution today. Traveling on icy or wind-scoured snow surfaces is the most effective way to avoid this avalanche problem.

Avalanche Discussion

Over the past 24 hours the Presidential Range has been exposed to significant amounts of wind after the most recent snow storm on March 12. Summit and ridgetop winds were 50 - 70 mph for the majority of the day yesterday with multiple gusts of over 100 mph. This will have created a mixed bag of snow conditions ranging from scoured snow surfaces, firm wind slabs, and softer pockets of sheltered snow. The condition in any given area will depend on the amount of protection that was offered from the wind. Expect areas of firm or old surface to have good stability, areas of firm wind slab to be stubborn to fail and propagate, and areas of softer snow drifts to be more sensitive to failure and propagation. These differences may be seen on a large scale, but also may all be seen within the confines of a single ski line. Careful and constant slab assessment will be required for safe travel in avalanche terrain today.

In many areas on steep, easterly aspects, it is likely to find a strong-over-weak snow structure which is reflective of initial storm conditions (snow and light winds), transitioning to rapid wind loading, and finally snow transport and redistribution with very high winds. If digging in the snow to assess stability, investigate snow above the old, icy crust layer and if a weak layer has the ability to propagate underneath the dense slab above. 

Finally, it is worth noting that the days are getting longer with more hours of sunshine and a more direct sun angle on many aspects, but especially on south aspects. Keep this in mind on days with warmer temperatures. A little sun can make all the difference between a snow surface warming, or staying cold. This increased heat can put additional stress on a slab, which can increase its potential to avalanche. It may be spring in the valleys, but it is not spring in the Presidential Range yet!

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.

Regions covered