Avalanche Advisory for Thursday 1-05-2012

Expires tonight at Midnight 1-05-2012

Tuckerman and Huntington Ravines have Moderate avalanche danger today.  Natural avalanches are unlikely and human triggered avalanches are possible.  We have not begun forecasting for the Lobster Claw, Right Gully, the Lower Snowfields, or Little Headwall in Tuckerman and the Escape Hatch in Huntington due to a general lack of snow in these areas.  Forecasting will begin for these areas when conditions warrant although avalanche activity may occur before this point.

This is about the latest 5 scale danger rating initiation for a season I can remember but the mountain finally thought it was about time, giving us enough snow to begin.  Over the past 6 days we’ve picked up snow daily adding up to 6.5” (17.5cm) on mostly SW to NW winds.  It is always impressive to see the Ravines’ lee terrain change so much from this nickel and diming precipitation.  This morning both Ravines are beginning at Low avalanche danger but the 1-3 inches (2.5-7.5cm) that are forecasted on W to NW winds from 45-60+mph (72-96+kph) should load lee slopes with new cold, low density snow.  Therefore expect changing conditions through the day and anticipate the steepest and largest slopes in the direct lee to be the most affected.  I would expect a number of locations to be on the upper end of the Moderate rating if the predicted snow accumulations become reality.  Due to the size and track length of a number of locations we decided it was time to move to a daily advisory.  Today’s weather forecast clinched it. The Chute and Left Gully are well ahead of neighboring locations in terms of size and development for issues in Tuckerman.  In Huntington Yale, Central and Odell are the most prominent areas of concern followed by the exits in South, Pinnacle and Damnation.  An area not mentioned above, but one that requires constant attention is the Lip through the Center Bowl of Tuckerman.  This area has many snow fields, benches, and pockets isolated from one another by ice and rock, many harboring very different conditions from patch to patch.  The degree of protection in the lee, the thickness of slabs, the size of each pocket all effect their stability.  Temperature gradients have also been high due to recent cold air.  This has created varying degrees of facet growth particularly in areas with thin snow coverage and a number of terrain features like rock and ice above and below the surface.   Up to another couple of inches (5cm) is expected tomorrow, once again on perfect loading W-NW winds so anticipate some stability issues to exist for the weekend if this plays out.  Also pay attention to a very icy trail from Pinkham to Hermit Lake.  New snow will help if we get enough, but could also hide slippery sections.  Micros spikes, ski poles or crampons may all be helpful.  Be sure to:

  • Check the avalanche advisory now posted daily due to the new snow forecast. 
  • Read the Weekend Updated posted tomorrow (Friday) afternoon/evening. 
  • Read a lesson learned summary on our incidents concerning a party of 2 skiers that were avalanched in Huntington’s Central gully on Tuesday with pictures and some analysis. 
  • Look at a number of pictures posted showing the Ravines and snow coverage that we took yesterday.

Check our website www.mountwashingtonavalanchecenter.org through the day uploading these bullets.

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 8:20am. A new advisory will be issued tomorrow.

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

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