Avalanche Advisory for Monday, December 12, 2016

Huntington Ravine has HIGH and CONSIDERABLE avalanche danger. Central, Pinnacle, and Odell Gullies have High avalanche danger. Natural avalanches are likely and human triggered avalanches are very likely. Very dangerous avalanche conditions exist. North, Damnation, Yale, South and Escape Hatch have Considerable avalanche danger. Natural avalanches are possible and human triggered avalanches are likely.

Tuckerman Ravine has HIGH and CONSIDERABLE avalanche danger. Sluice, The Lip, Center Bowl, Chute and Left Gully have High avalanche danger. Natural avalanches are likely and human triggered avalanches are very likely. Travel in or below this terrain is not recommended. Lobster Claw, Right Gully, and Hillmans Highway have Considerable avalanche danger. Natural avalanches are possible and human-triggered avalanches are likely. The Lower Snowfields has Moderate avalanche danger. Natural avalanches are unlikely and human-triggered avalanches are possible there. Little Headwall is not rated due to lack of snow and the amount of open water which remains unfrozen.

AVALANCHE PROBLEM: Wind Slabs will be the primary threat, especially later in the day as winds shift to the west and ramp up in velocity. Storm slabs will be a threat as well in steeper locations. Both of these threats will keep me out of the floor and, out of the runouts, of any steep, open terrain or gully today. Wind slabs this afternoon will create medium and large sized avalanches easily capable of burying you or sweeping you over cliffs.

WEATHER: About 4” of low density snow has fallen in Pinkham Notch as of 6:50 this morning. The caretaker at Hermit Lake reported 3” of 9% snow, mostly plates, on the board at 6:30am. It is currently snowing at a rate of about an inch per hour (S2). Winds on the summit are from the south and blowing in the 40 mph range. As the rate of snowfall diminishes mid-day, anticipate a quick shift in winds to the West where they will ramp up and quickly begin loading available snow into the Ravines on 50-70 mph winds. We appear to be on track to reach the 12” total snowfall which was forecast.

SNOWPACK: Heavily scoured areas consisting of a refrozen crust will serve as one of the bed surfaces for avalanche activity today. Mid storm and early storm layers will be the other. Avalanches may step down into pre-existing hard wind slabs as well. Those stubborn slabs are most likely not very well bonded to that melt-freeze crust in some areas so steeping down seems more likely than not. Lots of rocks, cliffs and bushes remain above or just beneath the surface but I wouldn’t count on them acting as anchors today. The Open Book and other features in the Lip and Center Bowl area remain unburied by blown in snow or avalanche debris and will break up the slope a bit and become terrain traps for avalanche debris. Crossing the Tucks Trail through the Lip would not be at all smart today, nor would being in the floor of Tuckerman Ravine. Expect Right Gully and Lobster Claw to quickly cross load and fill in more today. All in all it’s a good day stay at the resort or tour on low angle ski trails. Climbing in Huntington would be the last thing on my hit list.

The Lion Head Summer Trail remains the better route to the summit. We are keeping tabs on the development of the avalanche paths that threaten that trail and will switch to the using the winter route as snow continues to fill in things. Remember that the bridge work continues on the Tucks Trail so use the detour on the Huntington Ravine Trail. Some folks may opt to skin up the Sherburne so be on the lookout for them and for machinery when skiing or riding.

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 7:40 a.m., Monday, December 12, 2016. A new advisory will be issued tomorrow.

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

2016-12-12