Apr 282012
 

This advisory expires at 12:00 midnight, April 28, 2012

Tuckerman Ravine has Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. Evaluate snow and terrain carefully to identify features of concern. 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.

First it’s record warmth, then three feet of snow, then more record heat, and now more snow! When you see weather like that, you know it’s springtime on Mt. Washington. Last night the mountain received another shot of snow, totals yesterday at Hermit Lake were around 3” and the summit has recorded a little over 5” since snow began Thursday. There is currently more snow in the air and winds are blowing it into the ravine. With winds in the 60-90mph range, we can be fairly confident that snow has been transported into avalanche terrain. What’s less certain is whether or not this loaded into unstable slabs. There is very limited visibility at this time, so the Moderate rating is our best experience-based assessment given the various factors involved. These include the existence of sufficient bed surfaces, the amount of recent snow and densities, wind direction and speeds favorable to slab development, and a long history of closely monitoring snow conditions in this terrain. I would expect the greatest avalanche potential to be in the Lip, Center Bowl, and Chute areas. I suspect Left Gully and Hillman’s will have more variability, but anywhere you find a patch of new snow you should be ready to do your own stability assessments. As weather clears later today, you may find that the wind has scoured any new snow off of the icy old surface, which has great stability but is not without hazards of its own.

Below any new snow, the old surfaces will be hard and icy. These conditions are just perfect for seeing how fast a human being can slide downhill. 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 may be covering the openings to many of these. Falling into one of these on a day like today 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. The potential for FALLING ICE is diminished due to the cold temps, but that doesn’t mean you should ignore what’s above you. Pay attention to what’s up there, 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, 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

2012-04-28 Print Friendly

 Posted by at 8:37 am