Avalanche Advisory for Tuesday, March 15, 2016

This advisory expires tonight at 12:00 midnight.

All forecast areas of Tuckerman and Huntington Ravines have Low avalanche danger. Natural and human-triggered avalanches are unlikely. Watch for unstable snow on isolated terrain features. Lobster Claw, the Lower Snowfields, and Little Headwall are not posted due to a lack of snow in these areas.

AVALANCHE PROBLEM: Last night the summit received about 1.5″ of new snow with light SSE winds before changing to freezing drizzle overnight. The combination of insufficient snowfall amounts, unfavorable wind directions, and the transition to freezing rain and mixed precipitation is keeping avalanche problems largely at bay. The existing snowpack had been a very firm, slick, icy surface. This layer is likely to stay very firm underneath the new snow and perhaps a thin layer of softened snow from today’s temperatures and rain showers.

 Emerging spring hazards include:

  • Long sliding falls – Crampons are required in steep terrain. Snowshoes and microspikes are no substitute. Spring weather brings variable snow surface conditions that change by the hour and by aspect. Arresting a fall on an icy 30+ degree slope is practically impossible.
  • Crevasses, moats, and waterfall holes – Warm water flowing under the snow pack creates holes and thin spots in surface snow that are deep enough to injure or kill you.
  • Falling ice – This one is unpredictable. The best thing you can do is reduce your exposure by limiting the time you spend downslope from frozen waterfalls. Falling ice chunks can move with surprising speed and follow unpredictable trajectories.

All of these will be in play today and are harder to deal with when low visibility conditions exist. New precipitation can obscure these hazards, as well.

WEATHER: As mentioned, 1.5″ of snow fell yesterday, but this has transitioned to mixed precipitation and will become all rain by early today. Rain showers may bring up to 1/3″ of freezing rain, sleet, and rain through the evening. Expect poor visibility as well. If there is a silver lining to the cloud today, it will be the rather light wind speeds. Summit winds should stay below 40mph, possibly even becoming light and variable.

New snow that fell last week has melted off the Tuckerman Ravine Trail leaving ice in its place up to the Huntington Ravine Fire Road elevation. Microspikes or crampons are more than just helpful above Pinkham Notch. There really isn’t much opportunity to stay on snow on the Tucks trail…it is mostly wall-to-wall ice. The Winter Lion Head Route is now closed. The John Sherburne Ski Trail is closed below #2 hill (about 2/3 mile from the parking lot). Please respect the closure by walking over to the Tucks trail at the rope to reduce erosion on the trail.

Please Remember:

  • Safe travel in avalanche terrain requires training and experience. This advisory 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.
  • Anticipate a changing avalanche danger when actual weather differs from the higher summits forecast.
  • For more information contact the Forest Service Snow Rangers, the AMC at the Pinkham Notch Visitor Center, or the caretakers at Hermit Lake Shelters or the Harvard Cabin.
  • Posted 7:00a.m., Tuesday, March 15, 2016. A new advisory will be issued tomorrow.

Jeff Lane, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856

2016-03-15