Avalanche Advisory for Monday, January 27, 2014

This advisory expires at 12:00 midnight.

Tuckerman Ravine has CONSIDERABLE and MODERATE avalanche danger. The Sluice, Lip, Center Bowl, Chute, Left Gully, and Hillman’s Highway have Considerable avalanche danger. Natural avalanches are possible and human triggered avalanches are likely. All other forecast areas have Moderate avalanche danger. Natural avalanches unlikely and human triggered avalanches are possible.

All forecast areas of Huntington Ravine have CONSIDERABLE avalanche danger. Natural avalanches are possible and human triggered avalanches are likely. Careful snowpack evaluation, cautious route finding and conservative decision making are essential.

AVALANCHE PROBLEMS: Avalanche hazard will be increasing through the day. 3-6″ (7.5-15cm) of new snow on loading winds will build into wind slabs today. Persistent slabs due to a weak layer above the old rain crust also exists though it is impossible to determine exactly where these sugary facets will be a problem. Brief clearing yesterday afternoon revealed avalanche crown lines high in the Lip, low in the Lip above the Open Book, low and right of Chute and into Center Bowl. Other areas went unobserved. Areas will reload today on moderate then strong winds creating harder wind slab over a softer, potential failure layer.

WEATHER: Winds are currently out of the southwest at 55-65mph (85-105kph) and will shift west and increase in velocity to the 70-90mph (113-145kph) range, according to weather models and NWS forecasts. Snow showers and squalls are forecast, but currently, steady light snow is falling at Pinkham Notch and Hermit Lake. Southwest winds today will challenge Lion Head hikers who will be exposed from treeline to the summit. Temperatures will plummet again with the latest arctic cold front to sail through the area. Winds will most likely do some scouring of south facing Huntington gullies later this evening as speeds ramp up.

SNOWPACK: Two major avalanche concerns exist in our snow pack right now.  The new wind slab will build in size proportional to new snowfall today. Our nemesis, spatial variability, will show her ugly mug as these wind slabs shift locations as the winds shift, depositing snow in differing lee areas. As winds speed up it will break up and pack particles into denser slabs while building slabs further down in gullies and lower start zones. To complicate things further, the faceted weak layer, where it still exists, will be further stressed by the weight of new slabs. So, if you are a superhero impervious to traumatic injury, go dig a bunch of snowpits and let us know what you find. Until we get some clearing and calmer weather, our field work will be limited.

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 8:30 a.m. January 27, 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

2014-01-27 Print friendly