Avalanche Advisory for Monday 1-13-2014

This advisory expires at 12:00 midnight.

All forecast areas of Tuckerman and Huntington Ravines have Low avalanche danger. Natural and human triggered avalanches are unlikely. Watch for areas of unstable snow in isolated terrain features.

AVALANCHE PROBLEM: Isolated areas of wind slab are the avalanche threat today. As long as visibility holds, it will be pretty clear where these pockets of slab are located. They formed yesterday on top of the rain crust from 2.5″ of snowfall and strong winds. Expect them to be a mix of strong and well-bonded slabs as well as some that are more reactive to human triggering.

WEATHER: What an odd weather pattern we’ve been in recently! You can make up your own analogy about how moody Mother Nature has been these past few weeks, but the key points to remember are that we’ve had two significant rain events and not much for snow since that last good storm on January 2nd. Yesterday there was a mix of snow types, including graupel and other heavily rimed crystals, that added up to 2.5″ (6cm) on the summit. Winds were gusting in the 100mph range for several hours late yesterday, so most of that snow is nowhere to be found right now. Today, temperatures will rise above freezing all the way to the summit as clouds thicken in advance of a shot of precipitation tonight and tomorrow, which we hope comes as snow and not rain.

SNOWPACK: As mentioned, the snowpack has endured two heavy rain events in the last week. What is left behind is a grayish colored crust across two severely malnourished ravines. On top of this crust you’ll find areas of new wind slab from yesterday’s light snowfall in some isolated locations. In Tuckerman, you’re most likely to find this in the Chute, Center Bowl, and lower in the Lip areas. I hope to take a closer look at these pockets today, right now I’m working on an assumption that they have some stability problems. This is due to the underlying bed surface, the graupel that fell early in yesterday’s snowfall, and the increasing wind speeds later.

OTHER HAZARDS:
Long falls- The crust and lean snow coverage make it critical that you stay on your feet in steep terrain. Any fall that is not immediately arrested will have severe consequences. 

Incredibly icy trail conditions- Expect a lot of water ice on Mt. Washington, right from the moment you get out of your vehicle. The Tuckerman Trail up from Pinkham and the Sherburne Ski Trail have an astounding amount of water ice. What isn’t water ice is a very firm, slippery hard packed snow. I recommend traction devices for your feet and poles to help you keep your balance.

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 8:00a.m. Monday January 13, 2014. A new advisory will be issued tomorrow.

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

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