General Avalanche Advisory 12-30-2011

A new advisory will be issued when conditions warrant or within 72 hours.  Unless updated this advisory expires Sunday 1-1-2012 at midnight.

This is an early season GENERAL AVALANCHE ADVISORY for Tuckerman Ravine.  We have not yet begun posting advisories for Huntington Ravine due to the thin snow cover. Postings for this area will begin when conditions warrant.  General Advisories are issued when instabilities are isolated within the entire forecast area. However, avalanche activity may occur within these locations before the issuance of a 5-scale danger rating forecast. Under a General Advisory you need to make your own snow stability assessments when traveling in avalanche terrain. Within the General Advisory there are isolated snowfields that are growing in size and may harbor instabilities.

The mountains were a bit rugged on Thursday as the coldest shot of weather overran the region producing temperatures down to -15F with winds over 100mph and a peak gust of 122.  Although surface conditions are a bit thin, clearly winter conditions are here so plan accordingly with the appropriate equipment. The Tuckerman Ravine Trail from Rt. 16 to Hermit Lake is changing by the day.  Expect lots of growing sections blue water ice, so ski poles and traction devices and are extremely helpful.  Ice climbers should also expect ice dams to be an issue on routes. The high volume of moving water coupled with a rapid temperature drop develops these hydraulic demons.

Left Gully and the Chute have grown more quickly than other areas due to precipitation and wind history this early season. Wednesday’s new snow and Thursday’s high winds have brought in enough snow deposition to develop a decent start zone and track in these locations. Based on the current size of these bed surfaces, they have the ability to generate the largest potential avalanches on the eastern side of the mountain given the right future storm conditions.  Albeit smaller, numerous snowfields exist in the Center Bowl peppered between ice bulges and natural bench features in the terrain.  Although quite small in size they will likely see climber traffic due to the attraction of multiple ice routes and alpine options (see posted pictures at www.mountwashingtonavalanchecenter.org).  A great deal of spatial variability across these pockets exists because of the high number of slope angle changes, benches, and varying degrees of strong lee protection from past wind.  Anticipate pooled graupel, soft slab, hard slab, and thick icy crusts all on the same route. Conversely expect a number of areas to be barren of snow, such as Right Gully and the Lobster Claw as well as all traditional runouts because annual avalanche activity has yet to develop them.

Our day to day vigilance of the conditions is increasing as we prepare to move Tuckerman to 5-scale danger rating advisories and Huntington from no posting currently to a “General Advisory” soon.  In Huntington Ravine, Odell and Central gullies have grown the most followed by Yale and Damnation.  The approaches are still long and may be challenging to access these climbs.  Conditions are changing quickly and we’re getting closer to some more significant issues so check the latest advisory before heading into avalanche 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 AMC at the Pinkham Notch Visitor Center, or the caretakers at Hermit Lake Shelters or the Harvard Cabin.  Posted 9:00am 12-30-2011.

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

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