Avalanche Advisory for Sunday, 1-5-2014

Expires at 12:00 midnight Sunday 1-5-2014

Tuckerman Ravine has Moderate and Low avalanche danger. Sluice, Lip, Center Bowl, Chute, Left Gully, and Hillman’s Highway have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. Lobster Claw, Right Gully, the Lower Snowfields, and the Little Headwall have Low avalanche danger. Natural and human triggered avalanches are unlikely except in isolated terrain features.

Huntington Ravine has Moderate and Low avalanche danger. Central, Pinnacle, and South gullies have Moderate avalanche danger. Heightened avalanche conditions exist on specific terrain features. Natural avalanches are unlikely and human triggered avalanches are possible. All other forecast areas have Low avalanche danger. Natural and human triggered avalanches are unlikely except in isolated terrain features.

AVALANCHE PROBLEM: Similar to yesterday, windslabs are the primary avalanche problem. These were developed on Jan 2 & 3 after several inches of light density snow fell on the mountain. Yesterday we had significant concerns about the potential for a person to be the trigger for one of these slabs. Today we have a similar concern, although to a slightly lesser degree. We still feel that human triggered avalanches are possible in many locations, so choose your route carefully and consider the consequences of being swept off your feet even by a small avalanche.

WEATHER: We’re in the middle of a roller coaster ride with winter weather right now. After the bitter cold of two nights ago, today will seem quite mild by comparison. West winds will shift to the SW and diminish in speeds to 35-50mph (56-80kph). If it were not for the decrease in speeds, we might be thinking more about whether or not the shifted winds can find additional snow to load into the ravines. The shift is expected to coincide with the decrease in speeds, so we don’t think this will have much of an effect on snow stability today.

A WINTER WEATHER ADVISORY has been issues by the National Weather Service for 7pm through 10am tomorrow. By this evening, there should be some snow and sleet falling across the mountain. This will eventually turn to rain by Monday morning, and hopefully turn back to snow again before it ends. Total liquid water equivalent south of the Presidentials is expected to be around 0.75″ to 1.25″; to the north of the mountains there will be less, around 0.6″ to 1.0″. Either way, this is a significant amount of precip, with any luck we’ll get a majority of this in a frozen form. After this system passes, we will return to seasonably cold temperatures

SNOWPACK: We’re still waiting for more snow to fill in the ravines. Until this happens, expect a very discontinuous snowpack with variable conditions as you move from one snowfield to another. There are exceptions to this, such as Left Gully or Central Gully. These areas have long, continuous, and filled in snowfields especially compared to areas such as the Center Bowl or the Sluice. The northern gullies of both ravines are desperately wanting more snow. Snow conditions in these areas are thin, to say it best. Regardless of whether the potential bed surfaces are large or small, expect slabs to be poorly supported by the low density snow that fell with light winds at the start of the last storm.

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 0830 Sunday, January 5, 2014.  A new advisory will be issued tomorrow.

Jeff Lane, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-285

2014-01-05 print friendly