Posted 8:59a.m., Friday, January 14, 2011
Tuckerman and Huntington Ravines have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. The only exceptions to this rating are Hillman’s Highway and Left Gully in Tuckerman Ravine which have Low avalanche danger. In these areas, natural and human triggered avalanches are unlikely; however, you should watch for unstable snow on isolated terrain features.
We had a good storm on Wednesday, dumping 16” (41cm) of light density snow at the Hermit Lake snowplot. As great as that sounds, when I got a look into Tuckerman Ravine this morning I had to reset my expectations. Numerous small fracture lines can be seen around the ravines, however, in the aftermath the storm did not leave things looking as differently as I had hoped it would. A pattern exists for avalanche danger today that is similar in both Tuckerman and Huntington Ravine. Generally, the least amount of avalanche hazard will be found in the southern sides of the ravines, while the greatest avalanche danger is on northern slopes. In Tuckerman, Hillman’s Highway and Left Gully look much the same today as they did before the storm, hence their Low rating. On the other side of the ravine, in areas such as the Lobster Claw, Right Gully, Lip, and Sluice, new snow was able to hang on since the last avalanches ran through and they were more protected from the northerly winds. Cold weather is limiting the stabilization of these new slabs, even in the direct sunshine, and I would expect these areas to carry the greatest likelihood of a person triggering a slide. In the Center Bowl and Chute the slabs were more wind-affected than on the S-facing aspects, but not so much that they gained the strength they would need to be dropped farther down the rating scale. These areas also have the largest and most connected snowfields, which means you should be thinking not only about the snow you are traveling through, but also about the slabs you are connected to. Remember, the hazard today is directly related to human triggered avalanches. Options exist for avalanche-savvy mountaineers, but only if their willpower is strong enough to fight the tendency to be blinded to the hazard by the fresh snow and bluebird sky.
The distribution of avalanche hazard in Huntington is similar to Tuckerman. The northern gullies have the snow of most concern, particularly up high in the start zones of North, Damnation, and Yale. As you move from Central around to South there are fewer and smaller new slabs that were able to develop. Finding routes that entirely avoid unstable snow in the gullies is often hindered by the terrain in and leading up to the gullies, so pay attention to the changing conditions underfoot and view any new snow with suspicion. If you can find the hard icy old surface, that will be your best bet for avoiding stability problems.
We’ll be getting out into the field today, and this afternoon we’ll post thoughts for the upcoming weekend on our website, www.mountwashingtonavalanchecenter.org. We’ll also try to get some new photos up for your viewing enjoyment.
- 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.
- This advisory expires at midnight. 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