Tuckerman Ravine has MODERATE and LOW avalanche danger. The Sluice, Lip, Center Bowl, Chute, and Hillman’s Highway have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. Evaluate snow and terrain carefully. All other forecast areas have Low avalanche danger. Natural and human triggered avalanches are unlikely, but watch for unstable snow in isolated terrain features.
The Little Headwall has an open hole on skier’s right side below the steepest part of the route. Though this is the easiest way to ski out of the bowl, it remains a challenging run.
Huntington Ravine has MODERATE and LOW avalanche danger. Central, Pinnacle, and Odell have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible in those locations. North, Damnation, Yale, South Gully, and the Escape Hatch have Low avalanche danger. Natural and human triggered avalanches are unlikely. Watch for unstable snow in isolated terrain features.
4.3″ (11 cm) of new snow fell through the day yesterday and was blown or sluffed into lee areas and benches. Areas such as beneath the steeper drops in Right and Left Gullies and Lobster Claw, beneath the ice in the Center Bowl, the upper third of Hillman’s accumulated deeper snow. The same process was at work in Huntington Ravine below steeper sections of Central and Pinnacle gullies. The degree to which this snow formed slabs which could be triggered by a skier or climber is one concern today. Several reports of deeper snow in these areas yesterday as well as the tendency of rimed snow (graupel) to form weak slabs is a red flag this morning. Today’s heat will simultaneously reduce the threat of these slabs propagating long cracks and sliding but will increase the threat of this new snow sluffing naturally and underfoot in what could be heavy and tricky to manage point release avalanches. Skiers and climbers can mitigate this risk by choosing ascent routes carefully, staying out from under other skiers and climbers, and avoiding runouts.
Cold conditions last night most likely froze the older surface into a hard crust that will be a challenging travel surface in steeper wind exposed terrain. This surface will soften in the expected heat today. Low 30’s with light SW winds (5-20 mph) will allow surfaces to soften in the sun as well as in shadier areas as the temperature spikes this afternoon. Icefall is becoming a real threat and larger pieces of ice are beginning to threaten “Lunch Rocks” as well as the floor, the approach to Right Gully and the Sluice. North Damnation and Yale have a similar threat. Wise mountain travelers limit their exposure and their risk by choosing their route carefully.
Be prepared for potentially icy and difficult climbing. It’s a good idea when skiing in Tuckermans to carry a lightweight ice axe and crampons for easier and safer travel in addition to avalanche safety gear.
The Harvard Cabin is closed for the season. Hermit Lake is the only area in the Cutler River drainage where camping is permitted.
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 8:05 a.m., April 15, 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