Avalanche Advisory for Tuesday 4-16-2013

This advisory expires at 12:00 midnight.

Tuckerman and Huntington Ravines have LOW avalanche danger. Natural and human triggered avalanches are unlikely, but watch for unstable snow in isolated terrain features.

I’m finally feeling the onset of spring in the air. In part that’s because it’s currently colder at Pinkham than at Hermit Lake, but both are warm. Yesterday was a gorgeous sunny day in Tuckerman with most routes getting fairly heavy ski traffic. As expected, our concerns with stability of the most recent snow diminished most quickly on the sunny side of the  Bowl, such as in the Sluice and Lip. In many areas you can see where the ski tracks cleared away the fresh snow and left behind the gray colored older surfaces.

The temperatures have been above freezing in the ravine since yesterday. A cold front is passing today that will drop the cloud layer, kick up the wind velocities, and provide some afternoon rain showers, but it will not be cold enough to drop temps below freezing until after dark. Overall stability is good today, with a noteworthy exception that you should be aware of. In some areas where the new snow was able to collect more deeply, the heat may have not yet fully penetrated the snowpack. This would leave weakening wet slabs sitting on top of a weak mixture of dry snow and graupel. This problem will be isolated in nature, and there is a good chance that it won’t fracture out as a large slab. However, the nature of the terrain in which you may find this problem is such that you wouldn’t want even a small wet sluff to grab your skis or board and carry you downslope. Just imagine trying to swim through wet concrete while being pulled down a slope like Central Gully in Huntington. The piles at the bottom could be deep enough for burial, as well. I think this issue is isolated and will produce small avalanches or wet sluffs, but be heads up about it nevertheless.

Warm temperatures this week have gotten me thinking about the ANNUAL SPRINGTIME HAZARDS, such as FALLING ICE, UNDERMINED SNOW, and CREVASSES. These issues are going to be on display more and more in the coming weeks. Do your homework online to learn about these issues, or if you’re on the mountain and have questions, ask a Snow Ranger, volunteer ski patroller, or caretaker for information.

The Little Headwall has an open hole on skier’s right side below the steepest part of the route.  This hole has grown in the last couple days, and is threatening to collapse further. The same can be said for the snow bridges in the streambed above the Little Headwall. Use caution if you decide to ski out from the Bowl. Hiking out on the trail is a faster and safer option.

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 at 8:00 a.m., April 16, 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

2013-04-16 Printable