Avalanche Advisory for Monday, February 27, 2017

This advisory expires at Midnight.

 Huntington Ravine and Tuckerman Ravine have LOW avalanche danger. Natural and human-triggered avalanches are unlikely. The Little Headwall has returned to being a waterfall.

 AVALANCHE PROBLEM: Night before last, 2” or so of new snow created thin wind slabs in lee terrain. An inch or so of new snow may add to this problem later today. These pockets are unlikely to pose a problem in most areas but keep an eye out for thicker deposits drifted in behind the shelter of steep areas or at rollovers. The predominately icy snow surface is the more pressing concern. Firm snow will make for great cramponing on steep terrain, but refrozen boot tracks and glide cracks filled in with new snow create pretty nasty trip hazards. Arresting a fall with an ice axe on icy slopes only happens in the movies so travel carefully and consider using a belay and protection early on. Climbs in Huntington, especially northern gully climbs, took a real beating during the thaw. Be on the lookout for ice dams. In Tuckerman Ravine, melt channels mar the surface and the main waterfall is flowing near the Lip with a hole now open downslope at the top of the Open Book. This could become thinly bridged over by drifting snow.

WEATHER: West winds in the 60-80 mph range with higher gusts this morning will diminish a bit through the day. Temperatures will climb slightly from the current 10F to mid-teens on the summit. All in all, the mountain will see a return of winter conditions today before the next round of warm air moves in tomorrow followed by rain and freezing rain on Wednesday. Fog and low visibility will be a factor later today so don’t be surprised if the window closes this afternoon.

SPRING HAZARDS: With the warm spell last week, springtime hazards have emerged early this year. The cold temperatures over the past 36 hours have made the main hazard long, sliding falls, but be aware of the other usual spring suspects emerging in certain areas:

  • Ice dams – water flowing down Huntington gullies can build up pressure behind ice and burst.
  • Glide cracks, moats and crevasses have opened in places and are now concealed with the new snow, making identifying these extra difficult.
  • Falling ice and rocks become more frequent and sometimes larger as bonds holding things in place release.
  • Undermined snow over stream channels can be a problem in gullies but more of a danger lower in the tributaries. The generally warm winter so far hasn’t allowed many streams to freeze so this undermining is likely to emerge early this year. The waterfall has re-emerged in the Little Headwall and creeks are as open as they are bridged over with snow.

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  8:15 a.m., Monday, February 27, 2017. A new advisory will be issued tomorrow.

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

2017-02-27