Avalanche Advisory for Tuesday, 1-14-2014

This advisory will expire 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: Today’s primary avalanche problem is that we’ve lost so much snow that I’m considering a career change. If you’re traveling in either ravine today, you will have other more prominent hazards to contend with; see below for more details. As for avalanches, one potential threat stands out as unlikely but not impossible. Wet slabs may release due to excessive liquid water in the snowpack. Of all the avalanche problems, this one is dangerous and difficult to predictable by a backcountry traveler. If avalanche activity happens today, triggered either naturally or by a person, I would consider it an unusual event but not entirely unforeseeable. Regardless, avalanches are a notoriously fickle phenomenon. You should always travel cautiously in avalanche terrain in winter.

WEATHER: This morning feels very spring-like at Hermit Lake. It’s 39F (+4C) and there is grass showing outside of our cabin. Last night, temperatures never went below freezing at the middle elevations. Only the summit dipped below the freezing mark. Today’s forecast shows falling temperatures and some light precipitation. This is expected to begin as rain and sleet, but it’s possible that by the time this advisory expires, we will have 1-3” of new snow. Winds are expected to drop off in the afternoon.

SNOWPACK: Rain and warmth has hammered our snowpack this January. Currently, the entire snowpack is likely to be isothermal due to rain over the weekend and above-freezing temperature since midday yesterday. It’s a good time to be thinking of what lies beneath the snowpack. In many places in both ravines, it’s water ice. If the deep slabs become overly saturated with water, the slab may lose its ability to hang onto the steep icy slope. As mentioned, I think this possibility is an outlier, but still one that you should be thinking about. Rain and flowing water on Saturday blew out a good size avalanche in Yale gully, especially considering how little snow was in the gully to begin with. The debris pile here has a few garbage can sized chunks of ice mixed in with it. It’s yet another reminder of why we don’t recommend facing off against the threat of wet slab releases.

OTHER HAZARDS:

Falling ice- 24 hours or more of warmth can cause dangerous falling ice potential. Yesterday we witnessed this in both ravines, today I expect there to be some more. With very poor visibility, you won’t have much warning or any idea from where it’s coming.

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 ice. 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. Tuesday, January 14, 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

2014-01-14 print friendly