Avalanche Advisory for Wednesday, December 21, 2106

This advisory expires at midnight.

All forecast areas in Huntington and Tuckerman Ravine have LOW avalanche danger. Natural and human-triggered avalanches are unlikely. Watch for unstable snow on isolated terrain features.

AVALANCHE PROBLEM: The avalanche problem will be Wind Slab today. These will be isolated pockets, tucked under or in lee areas of terrain features. With good visibility, these slabs will be easy to identify when compared next to the dirty melt/freeze surface. This old surface will be the source of the greatest hazard today, providing the potential for long, sliding falls. Using crampons and an ice axe effectively on moderate and steeper terrain today will be crucial.

WEATHER: After several days of clearer skies, summit fog and wind will return today. West winds will decrease slightly from the current 60mph, shifting to the SW overnight. While the fog may lift during the morning, expect diminished visibility today, particularly as moisture arrives in the afternoon. Up to 1” of upslope snow is called for today, with another trace to 1” tonight. By morning tomorrow, a clipper system will cruise through, bringing unsettled conditions and measureable snowfall.

SNOWPACK: Our current snowpack is dominated by the melt/freeze event that took place over last weekend. This surface layer is bridging weaknesses that may exist lower in the snowpack. It is also acting as the bed surface for future avalanches. The dusting of snow on Monday has left a few pockets of instability in the form of wind slabs. These will be easy to avoid by making safe travel decisions. If snow falls today, be on the lookout for these isolated pockets to grow in size, but still remain small. Reports of great alpine climbing abound due to the firm snow surface. Bear in mind that even a slope of moderate angle can lead to a sliding fall. These are the days when roping up in 3rd and 4th class terrain may seem like a sound solution. Quick and effective self arrest skills will be critical for travel in any steep open terrain.

The Lion Head Winter Route is open and the most direct route to the summit from the east side of the mountain. The bridge that is still under construction on Tuckerman Ravine Trail now allows traffic making this the preferred hiking route to gain elevation from Pinkham. Please be careful of construction debris near the top crossover when descending the Sherburne Trail and be on the lookout for heavy equipment as work continues.

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 8:00 a.m., Wednesday, December 21, 2016. A new advisory will be issued tomorrow.

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