Tuckerman Ravine hasModerate and Low avalanche danger. Sluice and the Lip have Moderate avalanche danger. Natural avalanches are unlikely but human triggered avalanches are possible. The rest of forecast areas in Tuckerman Ravine have Low avalanche danger. Natural and human triggered avalanches are unlikely. Watch for unstable snow on isolated terrain features.
Huntington Ravine has Low avalanche danger. Natural and human triggered avalanches are unlikely except in isolated terrain features.
Yesterday, fieldwork confirmed that Thursday’s wind in excess of 100 mph (160kph) scoured and wind packed most of our snowfields into a firm surface for cramponing. Most areas are in the ankle deep range for boot penetration. It is the exceptions to this amount of boot penetration that are sources of concern for folks venturing into steeper terrain. While our snow stability is generally good, cold temperatures and steep temperature gradients in the snowpack have not allowed the snow grains to bond well under the slabs particularly near rocks and beneath cliffs. Steeper sections of climbs are most likely to harbor pockets of unstable snow so avoid these sections, especially if you find you are moving into an area of deeper snow. Areas listed as Moderate have the greatest potential to avalanche and due to the difficulty of skirting the potential trigger points; climbers might consider the many other routes available instead.
Right now at Hermit Lake, winds are dead calm and temperatures are a pleasant 00 F (-180 C). Full sun is providing excellent visibility. These are the conditions where the movie soundtrack turns to ominous minor key strings as the diabolical villain is waiting in the wings to spring his trap. In our case, the trap is falling temperature through the day and increasing wind speeds in the afternoon. While not unusually cold, or windy, -10 F air on 55-75mph winds is enough to push a minor incident like a sprained ankle, forgotten headlamp or malfunctioning crampon into something more serious. Don’t be the dummy in our film “Night of the Gnarly Ascent” that goes alone, unarmed, into the dark basement.
Still, today, like yesterday, is a decent climbing day with good visibility to allow for navigation and the micro-level route finding necessary to avoid those isolated areas of wind loaded snow and bullet hard old surface. A few notable areas in Tuckerman to give a wide berth are the Lip and the expanse of snow below it, as well as the bowl-like feature beneath Sluice ice and above Lunch Rocks where the summer Tuckerman Ravine trail traverses left into the Lip.
As mentioned over the past couple of days the old hard surfaces are still causing a traction problem in a number of locales. These old surfaces are camouflaged by newer snow in places and threaten skiers and climbers with long sliding falls.
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 8:45a.m. 1-26-2013 A new advisory will be issued tomorrow.
Frank Carus, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856