Avalanche Advisory for Tuesday, February 28, 2017

This advisory expires at Midnight.

Huntington Ravine and Tuckerman Ravine have LOW avalanche danger. Natural and human-triggered avalanches are unlikely in all forecast areas. Watch for unstable snow on isolated terrain features. The Little Headwall is no longer forecast this season as it is now an open river.

AVALANCHE PROBLEM: The avalanche problem today will be Wind Slab. This formed Saturday into Sunday on S shifting to W winds and can be located primarily under rollovers in the steepest terrain or in sheltered locations from west winds. With up to an inch of snow today, this wind slab may grow in size, however this increase should be negligible in affecting its stability. As this advisory expires at midnight, precipitation should turn to rain. With this changeover in precipitation, this wind slab will become saturated and become a Wet Slab problem. As the snowpack beneath saw 5 days straight of above freezing temperatures last week, the rain should only snow that has fallen since Saturday.

WEATHER: Winds are currently from the west at 40mph with temperatures in the upper teens. Temperatures should increase through the day as the cloud layer lowers and winds shift to the SW. An approaching warm front will bring moisture to the mountains this afternoon with up to an inch of snow before transitioning to rain around midnight. Rain tomorrow should provide an opportunity to stay inside and break out your edge file for the approaching cold snap this weekend.

SPRING HAZARDS: With the warm spell last week, springtime hazards have emerged early this year. Recent cold temperatures have mitigated some of these hazards (icefall) and increased others.

  • The refrozen snowpack is a prime surface for a long, sliding fall. Self-arresting will be very difficult, meaning climbers may want to consider breaking out the rope on your approach.
  • Ice dams – water flowing down Huntington gullies can build up pressure behind ice and burst naturally or more likely from the whack of an ice tool or crampon.
  • Glide cracks, moats and crevasses have opened in places and are now concealed with the new snow making locating these a challenge. The largest ones at the moment at under the cliff that separates the Sluice from the Lip, at the top of the early season ice climb called the Open Book, and on the approach to Central Gully near the climb called Cloudwalkers.
  • Undermined snow over stream channels can be a problem in gullies but more of a danger lower in the tributaries. The generally warm winter so far hasn’t allowed many streams to freeze so this undermining is emerging early this year. The Little Headwall is mostly open water, making exiting the Bowl on skis difficult.

Please come join us this Thursday, March 2 at Allspeed Cyclery and Snow in Portland for an evening with your avalanche forecasters. Our new Director, Frank Carus, will be talking about some of the changes going on within the avalanche center and how you can help make a difference. This event will be hosted by Friends of Tuckerman Ravine and will also feature one of New England’s own, Ben Leoni. You may know Ben from his film series Working for the Weekend produced by Ski The East. Ben will be talking about his time skiing in Quebec before we launch the most recent episode onto the big screen. This will be a great opportunity to meet our newest forecaster, Ryan Matz, as well as get a chance to socialize with people who love nothing more than talking about snow.

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  7:50 a.m., Tuesday, February 28, 2017. A new advisory will be issued tomorrow.

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

2017-02-28