Avalanche Advisory for March 26, 2016

All areas of Tuckerman and Huntington Ravines have LOW avalanche danger. Natural and human-triggered avalanches are unlikely.

AVALANCHE PROBLEM: The snowpack is locked up by a variable density rain crust that developed overnight. A remote threat of a deep weak layers creating a wet slab avalanche exists but would take a big trigger like water flowing into a slab, icefall or lots of people on a slope like the Lip or Sluice. It is unlikely given today’s weather forecast that today’s warming will reach far enough into the snowpack to cause stability issues like wet loose larger than a pocket in most other areas.

Long sliding falls are a significant threat today. Crampons are needed in most steep terrain. Microspikes are not adequate on anything steeper than a casual hiking trail. Refrozen, icy snow surfaces from recent rain are spread throughout our terrain. Arresting a fall on an icy 30+ degree slope is practically impossible. Soft skiing conditions will be entirely dependent on direct solar exposure, low wind speeds and air temperatures rising above freezing.

WEATHER: Today’s weather forecast is looking good for surface snow conditions to soften a bit in the sun in areas like Right Gully through the Lip in the mid-day timeframe. Unfortunately, the weather forecast indicates a really good chance for the surface snow to refreeze in the afternoon due shadows cast by intermittent cloud cover, increasing winds from the east or simply by slopes passing into shade as the sun travels across it’s low, early spring path across the sky. Timing is critical today as is the ability to choose an alternative route should conditions be different than you were expecting.

SNOWPACK: New, thin wind slabs avalanched sometime during the rain event in the left side of Center Bowl. Deeper down, our snowpack contained weak layers of graupel and early facets which did not release during the .48” of rain yesterday. The upper meter of snowpack is variable with strong, refrozen pencil hard slabs along with much lower density snow that recrystallized during last night’s clear sky with cold temperatures. Strong spatial variability will create a variety of conditions for riding and climbing. It will be a good day to stay fully engaged by picking safer travel lines considering the fact that spring hazards are emerging with some lingering winter concerns.

Other typical spring hazards include:

Crevasses, moats and waterfall holes – Warm water flowing under the snow pack creates holes and thin spots in surface snow that are deep enough to injure or kill you.

 Falling ice – This hazard is reemerging as warm days return. Lunch Rocks and the floor remain in the bullseye. Reduce your hazard by reducing time spent in these fall lines.

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 8:45a.m., Saturday, March 26, 2016. A new advisory will be issued tomorrow.

Frank Carus, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2716

2016-03-26 print friendly