This advisory expires tonight at 12:00 midnight.
Tuckerman Ravine has MODERATE and LOW avalanche danger today. The Sluice, Lip, Center Bowl, Chute, Right Gully and Hillman’s Highway have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. Lobster Claw, Right Gully, Lower Snowfields and Little Headwall have Low avalanche danger. Natural and human triggered avalanches are unlikely. Unstable snow may exist in isolated terrain features. New snow today may cause these ratings to rise.
Huntington Ravine has MODERATE and LOW avalanche danger today. Central and Pinnacle Gully have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. All other forecast areas have Low avalanche danger. Natural and human triggered avalanches are unlikely. Unstable snow may exist in isolated terrain features in these locations and the hazard may rise today due to new snow.
AVALANCHE PROBLEM: Wind slabs are the primary issue today. High winds peaking at 115 mph on Tuesday night and 97 mph Thursday did a good job scouring many areas to the old hard rain crust from 3 days ago. In other locations, existing wind slabs this morning are probably hard and not very reactive. New wind slabs forming through the day will have a greater potential to react to a human trigger and may grow significantly if forecast snow totals reach their high point of 3″. Pockets beneath steeps bulges and terrain features are locations to watch for these wind slab instabilities, as well as the upper portions of gullies and climbing routes.
WEATHER: Snow showers could drop 1-3″ on the summit today on moderate 40-55mph winds. Unlike higher wind speeds yesterday and Tuesday which scoured or densely packed our snow, today’s wind speed is right for transporting the new snow and depositing it into softer wind slabs. The exact timing of the shower activity is the crux and directly effects the avalanche hazard for the day. As snow shower activity begins and visibily diminishes, anticipate further challenges in visual assessment of the snow surface and subsequent route finding.
SNOWPACK: Light accumulations of snow on high winds through the week have resulted in scattered pockets of stubborn wind slab with some larger areas of concern in areas like Sluice, Center Bowl and the Chute. We start the day with prevailing hazards unchanged from yesterday. Last weekend’s rain followed by an Artic lock up has generally reset our snowpack. Surface instabilities will grow with fresh wind slab developing today on top of harder, more stubborn wind slab left over from light snowfall earlier in the week.
The very hard, slick surfaces that exist will make falling in steep terrain a real concern. Mountaineering experience in these conditions and the ability to self belay with an axe is critical in these surface conditions. Once sliding due to a slip, not even the most skilled mountaineer with a lifetime of experience could stop on our steeper snow slopes.
- 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 8:30a.m. Friday January 10, 2014. 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