Avalanche Advisory for December 26, 2014

Tuckerman and Huntington Ravines have LOW avalanche danger.  Natural and human triggered avalanches are unlikely except in isolated terrain features.

 AVALANCHE PROBLEMS: The potential for isolated areas of Wind slab is the problem to have eyes open for today.  Some scant snow yesterday and some isolated upslope snow showers today may be enough for high W winds to create thin pockets protected behind some terrain features.  This should be a remote issue. The dominate snow personality right now has been created by the recent rain and thaw event which is hitting the reset button in our mountain snowpack.  The saturated snow has been re-freezing deeper as overnight cold temperatures and extreme wind remove heat from the surface down. This is quickly making any older issues and problems that could have been categorized as persistent, moot.  Place your focus on newly developing instabilities that may occur on top of the crust during upcoming precipitation events.
WEATHER: Yesterday, very high winds pummeled the mountains as the front barreled through the region during Christmas morning.  Winds over 100mph (160kph) were common and the summit recorded a peak of 109mph (175kph) which made human outdoor observations difficult.  Nevertheless, the summit crew muscled the precipitation can back for melting and recorded 0.4″ of new snow yesterday, although they noted accurate collections were difficult. Very high winds will continue today, perhaps gusting to 110mph (176kph), along with some additional upslope snow.  Temperatures may rise a bit from the current of 14F (-10C), but not much.  Expect above treeline travel to be beyond difficult, to say extreme seems cliche, but it really describes it pretty well. We know you want to use that newly unwrapped winter parka in the alpine zone, but give it one more day.  Expect brutalizing winds to make it very difficult to deal with both icy surfaces and jumbled rocks, whether you’re on foot or crawling. One small problem could snowball into a desperate scenario when winds get to these levels.

SNOWPACK:  Well, the snow geek party is over for those inclined towards snow structure and crystal study. As the rain drains through the snowpack and and recent heat dissipates, the interesting layers (in 52.5″ total snowfall) from this month will be more or less pinned down by solid bonds leaving us an isothermal snowpack to start the new year. In the meantime, as winds lay down, enjoy the firm snow on the steep approach to climbs, but for goodness sake, don’t trip. The current icy snow surface will lend itself more to skeleton or luge racing than arresting a fall with an axe. Packed trails will demand micro-spikes and maybe a trekking pole or two but don’t forget that crampons are much more secure, both on your boot and on the ice, and may be needed on your chosen objective. Rain water and snow melt will most likely continue to flow in deeper channels of steep gullies so beware of increasing hydraulic pressure behind ice dams. On days like today, it is not unusual to see bloody paw prints on the trail so consider your dog’s pads when hiking on the chopped up, icy surface.

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 8:30 a.m. December 26, 2014. A new advisory will be issued tomorrow.

Chris Joosen/Frank Carus, Snow Rangers
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856

2014-12-26 print friendly