Avalanche Advisory for Thursday April 24, 2014

This advisory expires at Midnight.  

Although we just moved to a General Advisory during this midweek we are returning to a 5 Scale advisory. This is due to extent of the hazard in prelude to the weekend with additional precipitation over the next few days.  

Tuckerman Ravine has Considerable and Moderate avalanche danger. The Sluice, Lip, Center Bowl, and the Chute has Considerable avalanche danger.  Natural avalanches are possible and human triggered avalanches are likely.  All other forecast areas in Tuckerman have Moderate avalanche hazard. Natural avalanches are unlikely and human triggered avalanches are possible.  The Little Headwall is an open waterfall and has no rating.

Huntington Ravine is under a General Advisory. You will need to do your own snow stability assessments when traveling in avalanche terrain in Huntington. We are no longer monitoring conditions. A danger of falling ice exists, and will persist until it all comes down.

AVALANCHE PROBLEM: Wind Slabs and Storm Slabs are the main problem today due to overnight snow, snow today and high winds.  We expect a lingering avalanche problem due to this precipitation event and new rain/snow coming Friday night, Saturday, and Sunday.

WEATHER: As of midnight over 5″ fell in a short period and it has been snowing ever since adding an additional inch or two as of this morning.  Up to another 2″ is expected today.  High N winds will continue to build and shift, coming from the NW later today. Expect wind velocities over 100mph (160kph).   The cold air in the teens F, blowing snow, low visibility and very high winds have created full on winter conditions.

SNOWPACK: New snow is falling on an old rough and irregular melt freeze surface.  The hazard is almost exclusively in the new snow slabs that have developed over the past 12 hours and will continue to grow today.  Expect +/- 7 to 8″ of new snow on the summit to be loaded in on high winds causing slab development across all forecast areas.  Earlier in the winter when alpine areas are completely snow covered and bed surfaces are consistent and smooth we would have most areas bumped one rating higher.  But, between skier induced bumps and alpine bushes capturing some of this new snow, today’s ratings are appropriate.  Expect areas to be on the upper end of their rating depending how much new snow we receive exactly and what wind velocities we reach today.

OTHER HAZARDS:  With the current temperatures the icefall hazard has decreased a bit, but it should be on your mind, particularly the Sluice ice that looms behind Lunch Rocks.  Crevasses, that have begun to open up primarily in the Lip down towards Lunch Rocks, will likely be hidden by new snow making this hazard very difficult to assess.  The prudent traveler would avoid this areas due both to avalanche problems and crevasses.

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.
  • Posted 7:20 a.m. 4-24-2014. A new advisory will be issued tomorrow.

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

2014-04-24 Print