Avalanche Advisory for Tuesday, 4-23-2013

This advisory expires tonight at 12:00 midnight.

Tuckerman Ravine has Low avalanche danger. Natural and human triggered avalanches are unlikely. Huntington Ravine is not posted. We are no longer monitoring conditions in Huntington for the remainder of this season. You will need to do your own snow stability assessments. A danger of falling ice exists and will persist until it all comes down.

It was a long time coming this season, but we’re actually into a solid corn cycle right now. This is contributing to a very stable snowpack, so other hazards take center stage over avalanches at this time. The freezing overnight that allows this cycle to continue makes the snow surfaces very firm until they can soften up with the day’s warmth. Not only are they firm and icy, but the texture is very rough. Falling on this surface not only results in rapid acceleration, but it can scrape away deep layers of skin in short time. Long sliding falls are a serious hazard, but you are in complete control when it comes to the ability to prevent an accident. Having the skills to use the appropriate mountaineering equipment to keep you on your feet and on the slope, and staying within the limits of your climbing ability given the conditions at the time you’re there will help you mitigate the sliding fall hazard.

Be wary of ice hanging over the approach to the Sluice and Center Bowl which has held on tenaciously through a few warm days over the past weeks.  This ice will fall down in large chunks that roll unpredictably and with surprising speed.  Don’t linger at Lunch Rocks or in the floor of the ravine, it just isn’t worth it when sitting on your pack or another rock somewhere out of the fall line is an easy option. Hanging out under the ice is a game of Russian roulette.  Some days there are more rounds in the chamber than others but why play those odds at all if you don’t have to. Choose your routes carefully to reduce exposure to this hazard.

Crevasses have opened and will continue to open as our snowpack creeps downhill.  The slab of snow marking the lookers’ right edge of last Friday’s wet slab avalanche has a developing crack near the top. This slab is unsupported and is close to 6′ thick on a slope approaching 50 degrees. Though an avalanche here is unlikely, it is not impossible. If it does slide you don’t want to be anywhere near it. Additionally, the snowpack has begun to pull apart as it slowly creeps downhill. Crevasses are forming in the Sluice, Lip and Center Bowl areas. These slots can be deep enough to create a significant fall hazard and have been the scene of many accidents in the past, some of which were fatal. Give the crevasses and areas around any ice a wide berth.

Forest Service snow machines have been put away for the year and Snow Rangers are not on the mountain everyday due to other responsibilities on the White Mountain National Forest.  Though we are still closely monitoring conditions and are ready to respond to incidents, our response time will be greatly increased.  As always, you need to be ready to initiate and carry out your own rescue effort so be prepared with the knowledge and equipment to effectively help yourself or someone else in your party.

The Sherburne Ski Trail is closed about 0.75 miles uphill of Pinkham Notch. At the rope, you will need to cross over to the hiking trail and walk down to the parking lot. PLEASE do not walk or attempt to ski the trail below the rope–it isn’t built for foot travel and you will contribute to the erosion of this 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 Mount Washington Volunteer Ski Patrol, or the AMC at Pinkham Notch Visitor Center.
  • Posted at 7:30 a.m., April 23, 2013. 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

2013-04-23 Printable