Avalanche Advisory for Saturday, April 16, 2016

Tuckerman Ravine has LOW avalanche danger. Natural and human-triggered avalanches are unlikely. Lobster Claw, Lower Snowfields and Little Headwall are not posted due to lack of snow.

Huntington Ravine is under a General Bulletin. You will need to do your own snow stability assessments when traveling in avalanche terrain in Huntington. A danger of falling ice exists, and will persist until it all comes down.

 AVALANCHE PROBLEM: Due to the rain earlier in the week, and multiple melt-freeze cycles since then, avalanche problems are minimal. Minor sluffing or wet loose avalanches will mostly be small enough to be manageable but can create greater issues in steeper or untracked terrain. The following objective hazards are becoming significant players in safe route-finding:

  • Crevasses, moats, and waterfall holes – Water flowing under the snow pack creates holes, glide cracks (crevasses) and thin spots that are deep enough to injure or kill you. The climber’s right side of the Bowl, near and under “The Lip”, harbor the most and deepest holes. A skier fell near the top of the Lip yesterday and had a near miss with the Open Book hole. He, like most folks, was surprised to hear that the hole is around 70’ deep. It is unlikely that a fall into this hole, which lies in the fall line of the narrows of the run, is survivable. The waterfall hole flanking the narrows above is just as deep.
  • Falling ice – Large, falling ice chunks can move with surprising speed on destructive, unpredictable trajectories.The best thing you can do to reduce your exposure to this hazard is by limiting the time spent below these frozen waterfalls. “Icefall Rocks” (Lunch Rocks) and beneath Center Bowl (the Headwall) are in the crosshairs and are a bad place to sit, sled or hang around in. Sitting down lower on the Ravine floor near the entrance to the bowl is a great alternative to hanging out in “Icefall Rocks”.  Expect the falling ice hazard to increase as sun warms the Ravine.
  • Long sliding falls – Crampons, an ice ax, and the experience and skills to use them effectively are amost always required to travel safely in steep terrain. Snowshoes and microspikes are not a substitute and just “following a booter” is risky. Watch the runout in your potential fall line to pick a route that avoids frozen waterfall cliffs and rocks. Slopes are variable in firmness so have a plan of action in mind when the 45 degree slope you climbed becomes firm or even icy or the bootpack disappears, either from being filled in with sluffing snow or because it passes over an area of impenetrable snow or ice.

 WEATHER and SNOWPACK: High pressure continues today with sunny skies and temperatures expected to reach the mid-30’s F on the summit. Northeast winds at 20-35mph may slow the softening of the snowpack despite the full sun. Expect areas of crusty snow or ice until winds calm and ambient temperatures rise above freezing. Temperatures may remain cool enough for slopes which do not receive full sun all day to remain on the firmer side in places. Our snowpack has received several thorough soakings during the rain storms that we have received over the winter so the crust is pretty rugged in many places. Also, there are lots of areas where the ice cliffs and floes are emerging or were never really buried by our meager snowfall this year so stay heads up and expect variable snow conditions. As always, timing and choosing the right aspect at the correct time is the name of the game.

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.
  • Posted 7:35 a.m., Saturday, April 16, 2016. A new advisory will be issued tomorrow.

Frank Carus, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2716

2016-04-16