Avalanche Advisory for Tuckerman and Huntington Ravine

Posted 8:45a.m., Thursday, January 20th, 2011

Tuckerman Ravine has both CONSIDERABLE and MODERATE avalanche danger.  The Sluice, Lip, Center Bowl, and the Chute have Considerable avalanche danger.  Natural avalanches are possible and human triggered avalanches are likely.  The Lobster Claw, Right Gully, Left Gully, and Hillman’s Highway have Moderate avalanche danger.  Natural avalanches are unlikely and human triggered avalanches are possible.  The Lower Snowfields and the Little Headwall are still not posted.

Huntington Ravine has MODERATE avalanche danger.  Natural avalanches are unlikely and human triggered avalanches are possible.  The only exception to this is the Escape Hatch which has Low avalanche danger.

The mountain’s veil of clouds continues to hide her secrets this morning as we are anxious to see the results of almost 1 foot of snow over the past 48 hours.  An occasional thinning of fog has given us a little peak but not enough to get really good information.  The brief glance shows the mainly south wind event has helped Dodges, Hillmans, and the Lower Snowfields quite a bit however Tuckerman still remains mostly clandestine under a cloak of clouds.  Over the past 24 hours the mountain received another 3” (7.5cm) of 7% density snow with generally very light winds.  Velocities have been increasing this morning with the forecast expecting them to reach 50mph (80kph) before dropping this afternoon and shifting from the NW to the W.  In the meantime upwards of another inch (2.5cm) in anticipated.  So the main issue today is around 3-4” (7.5-10cm) of low density snow loading into a variety of left over slabs from the main portion of the storm.  Any newly loaded snow today should be touchy soft slab potentially responding negatively to human triggers, aka-avalanching.  This is possible in areas posted at Moderate and likely in areas posted at Considerable.  Natural avalanches have the greatest potential in Tuckerman from the Sluice over to the Chute where they are possible.  Depending on what slabs still remain a fracture and failure could step down into these older layers.  The biggest question we still have is what avalanched and what didn’t.  We can confirm South and Odell ran with possibly other Huntington areas, but this cannot be corroborated.  Questions surrounding exact specifics of a number areas still exist so we are leaning on what historically occurs in certain locales with the past days weather and what atmospheric conditions should occur today.  We will be in the field today trying to fill in some of these data holes.  With this said another 2-4” (5-10cm) is expected tonight and tomorrow with winds ramping back up tomorrow afternoon.  It is also possible Friday that we may hit winds able to move existing snow from above treeline which would become another loading source for the Ravines. 

In addition to all this we are about to plunge into the deep freeze for the weekend, very deep,… going Kelvin perhaps.  The MWO staff is alluding to perhaps the coldest temps seen over the past several years for the higher summits.  Wind speeds will also be quite stiff so expect extreme conditions requiring experience, quality equipment, and very good judgment.  I just wanted to give you a heads up in advance, but we will be discussing this as it develops in tomorrow’s Advisory and the evening weekend update.  These cold conditions will also keep any snow instabilities lingering through the weekend in addition to new facet growth.

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.
  • This advisory expires at midnight. 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

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