Posted 6:55a.m., Tuesday, January, 25, 2011
Tuckerman Ravine has Moderate avalanche danger today. Natural avalanches are unlikely and human-triggered avalanches are possible. The only exceptions to this rating are the Little Headwall and Lower Snowfields which both have Low avalanche danger. In these areas natural and human-triggered avalanches are unlikely.
In Huntington Ravine, Odell and South gullies have Moderate avalanche danger. Natural avalanches are unlikely and human-triggered avalanches are possible. All other Huntington forecast areas have Low avalanche danger. In these areas natural and human-triggered avalanches are unlikely.
Can you feel it? That’s right, the summit has pushed back above 0F(-18C) for the first time in three days. Hurrah! Snow showers have been recorded since midnight but little accumulation has occurred and no more than 1” (2.5cm) is expected over the course of the day. Transport of this new snow will occur with today’s moderate W winds so E aspects should receive some direct loading while most other areas see some degree of cross-loading. The windslab that develops as a result presents a new stability concern on top of the lingering issues of the past few days. Arctic temperatures have allowed limited sintering of snow grains or dissipation of stored energy. Most stabilization has been put off until warmer temperatures creep down into the snowpack and allow these processes to resume. Today’s forecasted ratings are identical to yesterday for this very reason. Winds were successful at pushing old snow around early yesterday but this largely subsided by late morning. The crown line from Saturday’s avalanche in the Center Bowl is still visible but watch for today’s W winds to try and bury it.
The areas of most concern in recent days have included the Lip and Sluice in Tuckerman, and in Huntington the approach to South Gully and the tops of Odell and Pinnacle. The areas that are still rated Low today may develop isolated pockets of new windslab in areas that are protected from W winds. Due to the cold temperatures the density of falling snow should be very low. This will allow transport at lower wind speeds and development of softer slabs that may be very reactive to a human trigger. The tops of Central and Pinnacle gullies will be two spots to watch for isolated pockets of this type of snow.
We recently switched over to the Lion Head Winter Route for summiteers and you’ll want to make sure you have your crampons and ice ax in addition to all your cold weather gear. Extra goggles, mittens and heated underwear are all a good ideas as well. A storm will be approaching the region tomorrow evening but at this time it looks like it will affect coastal areas more than the mountains. Stay tuned.
- 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.
Justin Preisendorfer, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856