Avalanche Advisory for Wednesday, April 15th, 2015

This advisory expires at 12:00 midnight.

Tuckerman Ravine has Low avalanche danger. Natural and human-triggered avalanches are unlikely. Huntington Ravine is under a General Advisory. You will need to do your own snow stability assessments when traveling in avalanche terrain in Huntington. A danger of falling ice exists, and will persist until it all comes down.

AVALANCHE PROBLEM: Avalanche danger today is Low as the past five days have had a stabilizing effect on the snowpack. Warm temperatures during the day and colder temperatures at night trend towards making an isothermal snowpack. The ravine has just about reached this point, creating several days in a row of Low danger. The largest stability hazard we see for today is sluff piles (skier induced wet loose) moving downhill and slowly generating more mass, becoming large enough to carry a skier, rider or climber to an undesired location. If you are traveling above cliffs, managing this will be important.

OTHER HAZARDS: Hazards other than avalanches are beginning to rear their heads and are worth looking for as much, if not more, than unstable snow.  Numerous areas of large ice have horizontal cracks forming and the Sluice ice, above Lunch Rocks, is already missing some chunks. Be aware of what is above you on a warm day and realize that eating lunch at Lunch Rocks puts you directly in the runout of large pieces of falling ice.  During this period of falling ice every year we do not recommend sitting at Lunch Rocks even though it may have a long tradition for you.

The snow is slowly moving downhill as a unified mass and is pulling away from cliffs, creating crevasses that while may not eat you whole yet, are certainly big enough to swallow a ski. These may change quickly so anticipate them growing in size. Undermined snow is creating challenges for exiting the Bowl. While the Little Headwall is still skiable, there is open water both above and below. The best exit from the Bowl may involve walking to Connection Cache and possibly farther.

WEATHER: Another nice day is upon us, although just a hair cooler than yesterday, with summit temperatures climbing to the mid 20’sF. Sun will once again reign with winds from the NW increasing to 60, gusting to 70mph.  Tonight we will refreeze again falling into the teens locking up the mountain snowpack.  Thursday will see a slight warm up with more sun before trending towards some unsettled weather for Friday and Saturday.

SNOWPACK: The past several days of glorious weather has been pushing us quickly towards a classic spring snowpack.  Initially, some around the clock melting raised some concerns for wet slabs as we transitioned from a cold snowpack towards an isothermal one.  Freezing nights have eased the wet slab potential allowing for a slower transition that snowpacks like.  Lock up will happen again tonight with the coldest night of the week in store. Expect the snowpack to become more stable and firm before daytime heating softens the surface.  Crampons and an ice axe are a good addition to avalanche PPE. Many carry both microspikes for the approach and switch to crampons for steeper terrain.  This is smart thinking as microspikes are not crampons. Skiers and climbers who get an early start, or finishes late, may encounter conditions conducive to long sliding falls. Be wary of a frozen snowpack lock up late in the day which can happen remarkably quick.  Don’t get too greedy for “just one more run” as the late day shadowline rips towards you across the terrain.

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 Mount Washington Volunteer Ski Patrol, or the AMC at the Pinkham Notch Visitor Center and Hermit Lake.
  • Posted 7:15 a.m. Wednesday, April 15, 2015. A new advisory will be issued tomorrow.

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

2015-04-15