Avalanche Advisory for Monday, January 9, 2017

This advisory expires at Midnight.

Huntington and Tuckerman Ravine have LOW avalanche danger. All forecast areas have Low avalanche danger today. Natural avalanches and human-triggered avalanches are unlikely. Watch for unstable snow on isolated terrain features.

 Lower Snowfields and Little Headwall are not rated due to a lack of snow but look for overhead hazard in Lower Snowfields which remains mostly tree covered except beneath Duchess.

AVALANCHE PROBLEM: Most slopes have been tested by skier and climber traffic over the past few days and yesterday only small pockets of wind slabs, built from the most recent light upslope snowfall, releasing on the southeast aspect of Duchess. This Wind slab will remain the avalanche problem of the day. These slabs are resting on an upper snowpack which consists of two crust with facets around them.  The crusts are generally breakable and create extremely variable travel conditions. You’ll find 20cm of soft snow next to firm wind slab beside super thin wind eroded crust. Pockets of the soft wind slab are the most likely thing to trigger but would be on the smaller side in most areas.

WEATHER:  Skies are clear this morning with a current summit temperature of -20F, 1F at Pinkham Notch. West-northwest winds are blowing around 60 mph on the summit. No new snow has fallen in the past 24 hours. Summit wind speeds will diminish and shift to the west-southwest through the midafternoon before slowly ramping up again. Temperatures will rise to near 0F later today. The next weather system on Tuesday is likely raise our avalanche danger due to the weak snow around the crusts in the upper snowpack.

SNOWPACK: Soft surface snow created some good steep powder skiing, at least by New England standards, in mid-gully elevations on Friday and Saturday. Unfortunately, wind action seems to have caught up to us and stiffened up or moved around the softer snow. There is a wide array of surface snow conditions and it will take careful route-finding to connect the dots. Continue to watch for the deeper ice crust from mid-December to grow facets and become a weak interface. So far this layer has proven well bonded but it is possible for the sustained cold temperatures to finally reach down to that layer and drive a faceting process to weaken this bond. The weak faceted snow surrounded the crusts nearer the surface lack a cohesive slab with any energy to propagate a crack. Safe travel practices, careful snowpack assessment and terrain management skills remain necessary to safely enjoy the skiing and mountaineering options that exist now in our terrain. The higher elevations near the tops of most gullies are fairly scoured and firm so long sliding falls remain in the mix of mountain hazards that you’ll face.

The Lion Head Winter Route is open and the most direct route to the summit. Please be careful of bridge construction debris near crossover 7 on the Sherburne Trail when skiing or riding.

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 the Harvard Cabin.
  • Posted 7:35 a.m., Monday, January 9, 2017. A new advisory will be issued tomorrow.

Frank Carus, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2713

2017-01-09