Avalanche Advisory for Sunday, 4-29-2012

This advisory expires at 12:00 midnight, April 29, 2012

Tuckerman Ravine has Moderate and Low avalanche danger. The Chute has Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. Evaluate snow and terrain carefully to identify features of concern.  All other forecasted areas have Low avalanche danger. Natural and human triggered avalanches are unlikely except in isolated terrain features. Lobster Claw, Right Gully, Lower Snowfields, and the Little Headwall are not posted due to an overall lack of snow in these areas. Huntington Ravine is under a General Advisory. You will need to do your own snow stability assessments when using avalanche terrain in Huntington. A danger of falling ice exists, and will persist until it all comes down.

Another clear, cold, and breezy day is in store for today. As far as snow stability goes, a mix of conditions exists across the terrain. On the easy side of stability assessments, there is a lot of very hard, very icy, old surface in many areas. You’ll recognize this type of surface by its grayish hue, in contrast to the creamy whiteness of the recent snow. The old surface is very stable, but its iciness makes for horrendous ski conditions. Moving away from old surfaces, you’ll start working into pockets of snow that fell in the early part of the weekend. These can be found in most areas around Tuckerman. On the whole, they’re isolated within each forecast area, which fits our definition of Low danger. However, you may still find instabilities in these pockets. The Chute is the one area that has enough new snow to be more than an “isolated terrain feature.” The new snow has filled in the entire upper half of the forecast area. If you find yourself drawn to this area today, you’ll need to ask yourself a couple questions. First, is there anyone up above who might trigger a slide while you’re climbing below? Second, do you have the skills and equipment for traveling in an area where it’s possible that you will trigger an avalanche? If you’re not sure about either answer, maybe you should choose a different line.

As mentioned, the old surfaces are hard and icy. These conditions are ideal for a fall to accelerate rapidly into an out of control sliding descent towards rocks and hard objects below. Nylon can be a great fabric for blocking the cold winds, but it doesn’t do much to slow down a fall. Numerous obstacles are in the runouts of just about all steep snowfields, so no matter what, DO NOT FALL IN STEEP TERRAIN! An ice axe and crampons are great tools to help keep you on your feet, but they do not guarantee safety in these conditions.

Among the obstacles mentioned above, CREVASSES AND UNDERMINED SNOW exist in many areas. New snow is covering the openings to many crevasses. Falling into one of these will almost certainly end poorly. Always climb up what you plan on descending so you can assess the hazards at a leisurely pace.  The Lip and Headwall have the largest crevasses but smaller slots have grown in the Sluice, Left Headwall, and the Chute. The lower sections of Hillman’s Highway have become discontinuous due the snowpack collapsing near the exposed rocks. FALLING ICE may not seem like a big deal on a cold day, but abundant sunshine can be enough to cause icefall to take place. Pay attention to what’s up above you, and think about what you’ll do if or when it falls.

THE TUCKERMAN RAVINE TRAIL IS CLOSED TO ALL USE FROM LUNCH ROCKS TO THE JUNCTION WITH THE ALPINE GARDEN TRAIL. This includes the Lip area as well as this section of the hiking trail. The trail to the floor of the ravine is open, as is the section from the summit down to the Alpine Garden junction. This annual closure is due to the magnitude of crevasses and undermining that develop in this area during the spring melt-out. A fall in this area would have severe consequences. The John Sherburne Ski trail is also closed to all use.

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 caretaker at Hermit Lake Shelters.
  • 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

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