Apr 212014
 

This General Advisory expires at 12:00 midnight, Wednesday, April 23, 2014.

Tuckerman and Huntington Ravines are under a late season General Avalanche Advisory. You will need to do your own snow stability assessments when traveling in avalanche terrain. General Advisories are valid for no more than three days, but may be updated earlier as conditions warrant.

Each season we reach a point where the day-to-day avalanche hazard is not significantly changing. We have reached this point in the 2014 season, for this reason we have decided to shift to a General Advisory. We will be monitoring the ravines, though with less of a snowpack-focused approach than we have for the past several months. For you, as a backcountry traveler, this means that you are responsible for assessing weather, snow, and avalanche conditions (this is always the expectation, but now we will have less daily information for you to utilize.) New snow, rain, or other weather may cause stability problems to exist even under a General Advisory.

At the time of this posting, the snowpack in the ravines is very stable. It has seen multiple melt-freeze cycles, which have added tremendous strength to the snowpack. There are both very warm temps and some rain expected in the next few days, so be thinking about the effects of a lot of running water throughout the snowpack and in the streams.

FALLING ICE is a very dangerous situation. The largest ice looms in the Sluice above Lunch Rocks, in the Center Bowl of Tuckerman, and throughout much of Huntington. Other areas pose this threat as well, though to a lesser extent. The best advice we can give is to not spend time underneath areas where ice may fall. Large rocks may provide some cover, but they have proven themselves in the past to be inadequate shields for people hiding behind them. Lunch Rocks is a hazardous location when icefall is a possibility!

CREVASSES AND WATERFALL HOLES are another potentially lethal hazard. Each season these form in many areas, the worst are in the Sluice, Lip, and Center Bowl. Many of these holes follow stream courses under the snowpack with icy water spraying around. Sunday evening we received our first report of a climber breaking through and dangling her body into a crevasse, thankfully she did not fall all the way in, and was able to climb out.

UNDERMINED SNOW is related to the hazard above. It occurs when streams have eroded away the snowpack from below, but left behind a bridge of snow. This bridge can collapse without warning under your weight, bringing you into the icy stream below. Give wide berth to areas that have already collapse or show signs of sagging or cracking.

LONG SLIDING FALLS are probably the #1 cause of injury each spring. Cold temperatures cause the soft corn snow to refreeze into a slick and solid mass of ice. We always recommend an ice axe and crampons for travel in steep terrain. You may not need them always, but if the unexpected happens these tools, and the ability to use them effectively, can save you from serious injury or death.

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 6:45 a.m. April 21, 2014. A new advisory will be issued Thursday, April 24.

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

2014-04-21 General Advisory

 Posted by at 6:46 am
Apr 202014
 

This advisory expires at 12:00 midnight.

Tuckerman Ravine has Low avalanche danger. Natural and human triggered avalanches are unlikely. Huntington Ravine is under a General Advisory. 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: Snow stability in Tuckerman is generally quite good at this time. Other hazards such as falling ice and long falls should get your attention today. Read on for more details.

WEATHER: Today will be an incredible contrast to yesterday as far as weather is concerned. Winds will be about as calm as they get on the mountain due to high pressure passing by the area. Temperatures are forecast to rise above freezing at all elevations. Best of all, the sun will be out. For perspective, yesterday morning visibility ranged from 50 to 100 feet for many hours without a break, surfaces were rock solid ice with no hope of softening with temps below freezing.

SNOWPACK: The snowpack starting today is solidly locked into the freeze portion of a melt-freeze cycle. This will quickly change as sun and warmth begin to have their way with frozen layers. I expect all surfaces to become softened early, then maybe even become deeply wetted as the day moves on.

ICEFALL SEASON IS HERE. There is currently a large chunk perched threateningly over Lunch Rocks. This will almost certainly crash into the rocks if it were to fall today. There are many safer locations to relax between runs or hang out and watch the action…Lunch Rocks is not one of them. Icefall may occur from other locations as well, so stay aware of this potential.

CREVASSES AND HOLES IN THE SNOWPACK have been late in emerging this season. They will come out and become a problem at some point. Today might be the day. Ask if you have questions about where these typically open up because you’ll have a hard time seeing them until the snow gives way under your feet.

The best exit from the bowl is to hike down the trail. The Little Headwall is blown out completely for the season. The streambed has also deteriorated beyond what a reasonable person would call “skiable”. Trying to negotiate the trees on either side is difficult at best, dangerous at worst, and your judgment will be questioned by anyone on the hiking trail or the porch who happens to see you flailing in there.

The Lion Head Winter Route is still open. This is a steep icy trail. An ice axe, crampons, and the ability to use these tools effectively are highly recommended. Lightweight trail crampons lose their effectiveness in terrain this steep!

The John Sherburne Ski Trail remains open to the parking lot. Expect lots of bare patches, icy sections, and enormous bumps throughout 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.
  • Posted 7:00 a.m. 4-20-2014. 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

2014-04-20 Print Friendly

 

 Posted by at 6:49 am