Avalanche forecast

Presidential Range

Mount Washington Avalanche Center
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Avalanche danger

Sat
Alpine
1 · Low
Treeline
2 · Moderate
Below
1 · Low
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Out of date — this forecast expired 5 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

New snow yesterday and wind overnight have increased the avalanche danger. Human triggered avalanches are possible on wind loaded aspects and below steep terrain features. Look for smooth pillows of wind drifted snow in these areas. In many places, the new snow barely covers hard, refrozen snow and sun crust so carry the proper tools if venturing out today, including crampons and avalanche rescue gear. Avalanche danger is MODERATE today where  wind blown snow has accumulated. A long sliding fall hazard exists elsewhere.

The Winter Lion Head Route is the most direct route to climb to the summit from Pinkham Notch. The Tuckerman Ravine trail through the Bowl, and the Lion Head Summer Trail are much more exposed and pass through avalanche terrain.

The Inferno Pentathlon tomorrow will have a hike then ski component, possibly in Tuckerman Ravine and definitely on the John Sherburne Ski Trail. Please be mindful of increased traffic on trails.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    You’ll find some wind slabs tucked under the ice in the center of Tuckerman Ravine, the top of Right Gully and Yale and along the sides of avalanche paths in the Gulf of Slides today. Loading is occurring very early this morning in addition to mid-day yesterday when the snow fell. The northerly direction of the wind this morning is a key data point to consider. The limited snowfall amounts will limit the size of the new wind slabs but the icy surface the slabs rest on increases the consequences of a slide. These slabs are likely to be moving towards stubborn but may be reactive early today. The first warming of these slabs in the sun tomorrow afternoon will also be a concern.

Avalanche Discussion

Yesterday's snowfall met and possibly exceeded the upper end of the forecast and may have made yesterday's low rating a particularly exciting one in some wind loaded areas. Observations from an avalanche course in the fielddemonstrates well that risk assessments should be ongoing in the field using various forecasts as a starting point for decision making. This approach should allow flexible route choices based on current snow and weather conditions at the time with attractive alternative plans that respect the safety margin demanded by the environment. Weather and snow are dynamic, particularly now as winter and spring conditions trade places from day to day and hour by hour.

Collecting snow in our environment is tricky for many reasons, usually related to the wind, but more recently due to a warming snowpack which drives rapid settlement of snow on the ground. The snow depth instrument at Hermit Lake paints the clearest picture of total snowfall that occurred yesterday since this data is recorded hourly in a wind sheltered location. This device takes more regular “snapshots” that can then help guide our understanding of what is happening in the alpine. Uncertainty exists in today's avalanche problem in terms of both size and sensitivity due to the warm snow that fell yesterday which may have resisted transport by the wind to some degree. The icy surface in the alpine combined with the increasing wind and very cold temperatures steered my thinking towards the total amount of snow (presumably 2”) being available to build slabs, possibly in the 12-16” thick range in specific areas. By mid-day it also seems likely that these wind slabs will be on their way towards becoming stubborn and later unreactive due to the rounded grains from which they were constructed. But you’ll need to be the judge of that, likely while wearing crampons standing on an adjacent ice crust.

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Listen to the weekly MWAC Outreach Podcast provided by Ski The Whites. Discussions include snowpack information, weekend outlook, and general avalanche related info. 

 

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The Harvard Cabin is open for camping only with no entry allowed inside the cabin. There is no access to the breezeway at HoJos.

Please Remember:

  • Safe travel in avalanche terrain requires training and experience. This forecast is just one tool to help you make your own decisions in avalanche terrain. You control your own risk by choosing where, when, and how you travel.
  • Avalanche danger may change when actual weather differs from the higher summits forecast.

For more information contact the US Forest Service Snow Rangers, AMC visitor services staff at the Pinkham Notch Visitor Center, or the caretakers at Hermit Lake Shelters or seasonally at the Harvard Cabin (generally December 1 through March 31). The Mount Washington Ski Patrol is also available on spring weekends.

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