Avalanche Advisory for Wednesday, January 27, 2016

This advisory expires tonight at 12:00 midnight.

All forecast areas of Tuckerman Ravine have LOW avalanche danger.  Natural and human-triggered avalanches are unlikely.  Watch for unstable snow in isolated areas.  Lobster Claw, Lower Snowfields, and the Little Headwall are not posted due to lack of snow cover. Exercise caution in these areas.

Huntington Ravine is under a General Avalanche Bulletin. General Bulletins are issued when instabilities are isolated within forecast areas and are issued every three days or earlier if conditions warrant. Forecast areas in Huntington have less well-developed snowfields to produce avalanches than Tuckerman, but understand instabilities in these smaller locations may exist.  It is critical that you assess snow and avalanche conditions if venturing into Huntington.

AVALANCHE PROBLEM: The primary avalanche problem today is windslab. The most concerning situation to watch out for is the development of new wind slab, if accumulating upslope snow materializes. These would be found in strongly sheltered areas first, then growing in more wind exposed areas later. Secondly, pay attention to the firm, hard wind slabs created during high winds almost 7 days ago. We are in a situation with very lean snow coverage in most areas, which creates an inherently variable snowpack. Your most likely interaction with unstable snow of this type will be near the thinner margins of older slabs. Trigger something from one of these weak points is not completely out of the picture, so you should still stay vigilant. One situation to watch for is being able to kick through the firm slab into weak snow beneath.

WEATHER: Another day…another day hoping to see the upper end of the upslope snowfall potential. We expect there to be scattered snow showers in the mountains today, possibly bringing up to 2″ (5cm), but the more likely scenario is that we’ll see only lighter accumulations. Winds will start strong and begin to diminish somewhat through the day. You can expect some blowing snow, but how much will largely depend on how much snow has fallen.

It’s been a slow week for snow accumulations. Very light snowfalls over the past eight days have totaled only 1″ (2.5cm) of snow on the summit. At Hermit Lake you wouldn’t even know that it snowed at all. Our best hope for something in the near future looks to be a clipper system passing by on Friday, but don’t get overly excited about this one.

SNOWPACK: Yesterday’s field work left Helon and I rather unimpressed by the snowpack. One thing that is for sure, there is a lot of variability out there. Some locations on S-facing slopes had a shiny sun crust, others were just firm wind packed snow. Helon dealt with blowing snow creating sluffs and some thin reactive slabs over in the left side of the headwall, but the overall pattern was for a thick hard slab. In Left Gully, he thought he might break his shovel trying to dig into the surface layer and would have preferred digging with a snow saw. You may find areas where faceted snow is forming underneath the hard slab, near a buried crust. This will be something that we’ll need to keep an eye on in the future. But for now, it doesn’t appear to have much effect on current stability.

Huntington Ravine remains under a General Bulletin. It is important to remember that avalanches can occur under a General Bulletin. The biggest potential areas are the snowfields in Central and South Gully as well as at the base of the ice in Pinnacle and Odell. The northern gullies of Yale, Damnation, and North are primarily ice and contain very little snow. The Lion Head Winter Route is now open. Bear in mind this is not a hiking trail and mountaineering sense should be in your backpack, right next to you crampons and ice axe. The Sherburne Ski Trail is skiable top to bottom but is in very rough shape. Anyone care to share the story of the blood we found sprayed all over the trail yesterday? We are baffled.

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 6:15 a.m. January 27, 2016. A new advisory will be issued tomorrow.

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

2016-01-27