General Advisory for Sunday, 12-23-2012

This is a GENERAL AVALANCHE ADVISORY for Tuckerman and Huntington Ravines.  A new General Advisory will be issued if conditions warrant or within 72 hours of this release.

A General Advisory is issued when there are limited instabilities within the entire forecast area. Snowfields in the ravines are growing in size and  unstable slabs may exist in these locations. Assessing snow stability for yourself as you travel through the mountains is always the right thing to do. Although we have not yet begun issuing daily danger ratings, avalanche activity may still occur. Remember that even a small avalanche from a small snowfield can be quite dangerous, especially in early season conditions such as these.

Overall on Mt. Washington, typical winter conditions were late in arriving. There was scant snow to be found in early December, but from Dec. 16th to the 22nd, the summit has reported a total of 32.2″ of snow. Unfortunately there were some warm temperatures, rain, and mixed precipitation during this time, so this number needs to be seen in the full context of what’s happened here. At lower elevations, we observed much less snowfall and more rain and melting. Around the mountain you’ll find a mix of surfaces, which may include water ice, breakable crusts, strong supportive crusts, and dust on crust, as well as areas where new snow has accumulated more deeply due to wind loading or funneling down a gully. Pay attention if you find an area where the snow has been able to accumulate, because it’s likely to be sitting on top of either a crust or on water ice, neither of which likes to bond well with new snow and could avalanche on you.

Looking ahead at the weather over the next few days, a high pressure system is in the cards, but this doesn’t mean sunny beach weather is here. Expect the weather to be cold and windy as low pressure exits on Sunday and Monday. Tuesday’s forecasts currently call for some light snow showers, but the real gift in Santa’s bag is on Wednesday night and Thursday. The NWS is talking about increasing confidence for a significant winter storm during this time. This may be the storm that pushes us into our daily forecasting routine, but it’s still several days away so we’ll have to be patient for now.

In case you were wondering, the Sherburne does have snow and is skiable from top to bottom. However, it is a backcountry trail, so there is a lot of brush and small trees that are not yet buried. There are also several water bars that contained open water as of Sunday, thanks to the rain on Thursday 12/21.

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 9:00, December 23, 2012.

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

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