Avalanche forecast

Presidential Range

Mount Washington Avalanche Center
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Avalanche danger

Fri
Alpine
1 · Low
Treeline
1 · Low
Below
1 · Low
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Highlights

Look for eastern aspects in the middle elevations to have drifted slabs in isolated locations that could pose a risk for human triggered avalanches. Tonight’s mixed precipitation will increase the chances for triggering a small avalanche but should not add any additional risk for large avalanches. Stick to wind scoured slopes for the safer ski options if traveling in steep terrain.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    1–1.5

    Wind drifted slabs from recent snow can be found in isolated locations of the middle elevation on eastern aspects. These slabs can vary in thickness from about 2 inches to 2 feet, and are found in wind sheltered areas. The hardness of the wind transported snow ranges from 4Finger to -Pencil with subtle density changes throughout. Pillows of recently drifted snow are more plump in the middle of the gullies and lower on the slope. Graupel and rimed particles comprised most of the newly formed slabs with wind broken precipitation particles holding them together.

    Many of the slabs tested were resistant to propagation and it took moderate force to initiate failure. Surrounding an old melt/freeze crust, approximately 24cm deep, facets have formed during cold and dry conditions leaving this layer of snow weakened. Not surprisingly this failure has been seen repeatedly in stability tests over the past week. Although this layer has grown stronger and is taking noticeably more force over time to collapse, it is still on our radar as a weakness plane for future snow loads.  

Avalanche Discussion

Today's forecast is layered with temperature fluctuations, mixed precipitation forms and some uncertainty as to where the freezing level will migrate. Today afternoon snow showers could leave 2 to 3 inches on the slopes with moderate southwest winds.  Tonight rain is forecasted in the low elevation band and could potentially creep upslope beyond the middle zone reaching the uppermost elevations. With such low percentage precipitation potential it is unlikely that we will see enough drifting to create large avalanches this afternoon.

Yesterday in the ravines extreme winds pummeled the slopes, eroding away many of the recently formed slabs in the upper elevations. In the middle elevation isolated pillows of drifted snow grew with wind loading and graupel pouring downslope. The growing slabs were variable in thickness and hardness as you traveled with only minor cracking and few signs of instability. Areas that received prior sun exposure, such as Right Gully, harbored thin and degrading crusts that were noticeable in stability tests but showed poor propagation potential. 

Today you are likely to find scoured slopes with drifted, wind-firmed slabs in leeward isolated terrain features. This evening and overnight expect rising temperatures and a change in precipitation form, from wet snow to freezing rain and somewhere in between. With all the variables considered we are possibly riding just below the line of Moderate this afternoon. Take the time to make your own assessments regularly and collaborate group decisions.

The Lion Head Summer Trail is CLOSED due to increased avalanche hazard. The Lion Head Winter Route is OPEN and the most direct route to the Mount Washington Summit from Pinkham Notch. 

OBSERVATIONS: Please consider submitting an observation 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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