This advisory expires at 12:00 midnight, February 3, 2013.
All forecast areas of Tuckerman Ravine and Huntington Ravine have Low avalanche danger today. Natural and human triggered avalanches are unlikely. Watch for unstable snow in isolated terrain features.
Snow stability assessment will be about as straightforward as it gets for climbers in the ravines today. Though some new snow fell yesterday on light winds (1.5” or 3.8cm reported on the summit), it was only enough to create a thin veneer on the trails and gullies. Old snow surfaces prevail in all but select drainage channels, benches and low angle sections of ice climbs where the light snow was able accumulate. The pockets of new snow are easy to distinguish from the old, gray refrozen surface that is a product of our most recent January thaw.
Bright blue skies and bright sun dominate at 7:30am but clouds will thicken and lower in the afternoon, reducing visibility and spawning some snow showers. Be on the lookout for more snow accumulating in pockets which may push our Low hazard forecast into the upper reaches of its definition. Otherwise, light winds and cold temperatures will provide a nice day for a winter outing.
Water is still running under ice climbs in some areas. Though the hazard is diminishing with sustained cold temperatures, the possibility for bursting an ice dam still exists. Pinnacle Gully is now all ice with little snow climbing. Lots of rocks, potentially loose, were uncovered during the recent thaw so use caution, protect your belayer and be flexible in your plans to avoid climbing under other parties.
As mentioned many times before, the old hard surfaces are slippery. These old surfaces are camouflaged by newer snow in places and threaten skiers and climbers with long sliding falls. The Tuckerman Ravine trail has significant stretches of water ice erupting onto the surface or just covered by 1cm (.4”) of new snow. The Sherburne trail is better suited to a bobsled than skis, so don’t bother with your boards. It does have decent coverage from top to bottom still, but it is very icy and choppy. There are numerous patches of blue water ice, some exposed rocks, and some areas where slush has run over the trail.
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 8:00a.m., February 3, 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