Avalanche Advisory for Tuesday, January 30, 2018

Huntington Ravine has LOW avalanche danger. All forecast areas have Low avalanche danger. Watch for unstable snow on isolated terrain features.

Tuckerman Ravine has LOW avalanche danger. All forecast areas have Low avalanche danger. Watch for unstable snow on isolated terrain features. The Little Headwall is not rated due to a lack of snow.  The Lip still contains a large void in the snowpack from the wet avalanche on January 12 or 13.

AVALANCHE PROBLEM: A firm and icy snowpack with some areas of wind slab summarize our terrain right now.  The wind slabs that are out there are unlikely to produce an avalanche but are worth evaluating for signs of a weak bond to snow beneath or a tendency to sustain a crack along the surface. These wind slabs are easily visible and identified by contrast to the gray and dirtier looking, refrozen snow.

WEATHER: A fairly benign day is in store for the mountains.  High temperatures on the summits will be in the single digits with a steady northerly wind.   Some light snow may come through tonight with a better chance on Wednesday night, which may bring a couple of inches of replenishment.  While we can rejoice at the forecast of colder air at the onset of the weekend, significant snows are not looking to turn this icy rock around anytime soon.

SNOWPACK: The Ravines are dominated by a very hard icy surface with sporadically distributed wind slabs discussed in above.  These wind slabs have not proven to be very reactive during our stability tests   which generally showed that the wind slab was well bonded to this icy surface. Nearer the surface, firmer (1F) wind slab over the thicker 4F slab created a clean shear at the interface between these two layers but neither layer showed any desire to propagate a crack much beyond your feet. Snow and ice climbs are in great shape now and today’s calm weather and good visibility provide a good opportunity to enjoy them.  The firm snow allow for efficient cramponing but self-arrest must occur immediately if you slip, otherwise a long sliding fall will likely ensue.

Microspikes and crampons are key tools for travel today. Crampons are needed on the steeper slopes and above treeline. Conditions on the Sherburne Ski Trail remain grim though passable for those desperate for a lap.

Please Remember:
• 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 Harvard Cabin.
• Posted 6:15 a.m., Tuesday, January 30, 2018. A new advisory will be issued tomorrow.

Brian Johnston, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856

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