Avalanche Advisory for Sunday, March 27th, 2016

This advisory expires at Midnight.

Tuckerman and Huntington Ravines have LOW avalanche danger. Natural and human-triggered avalanches are unlikely.

AVALANCHE PROBLEM: Yesterday, we had some lingering wet slab and wet loose concerns in a couple of places with the expected warm up for Saturday. With another day for the snowpack to go through the melt freeze process, and lots of ski traffic compacting heavy slushy early corn in specific locations, this concern is even more remote today. The avalanche hazard today is taking a back seat to the other spring issues mentioned below.

WEATHER:  Today will start in the clear with increasing clouds filtering in, which should limit afternoon heating of the snowpack compared to yesterday.  Temperatures will rise to the mid 30’sF on the higher summits with winds from the S, shifting around to the W, and slowing increasing to 35mph.  For the prepared, it will be a nice day to be in the mountains.  Tonight, moisture will move into the region with rain expected all the way to the Washington summit on Monday.

SNOWPACK: Following Friday’s warm up, rain, natural avalanche activity in left Center Bowl, cold nights, and yesterday’s ski traffic, the snowpack has consolidated and stabilized. We have good confidence that we have made it through the vast majority of lingering stability concerns. There are a few locations that did not see ski traffic yesterday. These locales will be obvious with good visibility today. Keep the potential for a skier induced wet loose sluff in the back of your mind, albeit a remote possibility. Avalanche potential or the chance of minor waterfall blowout will rise tomorrow with rain, potentially heavy at times.  However, the snowpack should handle this water infiltration well if we stay to the forecasted water amounts in the Quantitative Precipitation Forecast (QPF).  The wet snowpack will then freeze again Monday night with 1-3” of snow to follow, perhaps creating some pockets of instability for Tuesday.

Other typical spring hazards include:         

  • Crevasses, moats and waterfall holes – Water flowing under the snow pack creates holes and thin spots in surface snow that are deep enough to injure or kill you.
  • Long sliding fallsare a significant threat today. Crampons are needed in most steep terrain. Microspikes are not adequate on anything steeper than a casual hiking trail. Arresting a fall on an icy steep slopes is practically impossible. Soft skiing conditions will be entirely dependent on direct solar exposure, low wind speeds and air temperatures rising above freezing.
  • Falling ice This hazard is reemerging as warm days return. Lunch Rocks and the floor remain in the bullseye. A better name for Lunch Rocks is “ICEFALL ROCKS” as it get hammered by ice every season it is not a good place to hang out and the location for many serious injuries over the years.

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 8:00 am, Sunday, March 27, 2016. A new advisory will be issued tomorrow.

Christopher Joosen, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2716