Avalanche Advisory for Monday, January 2, 2017

This advisory expires at midnight.

Huntington Ravine has MODERATE and LOW avalanche danger. Central, Pinnacle, Odell, South, and Escape Hatch have Moderate avalanche danger. Natural avalanches are unlikely and human-triggered avalanches are possible. Heightened avalanche conditions exist on specific terrain features. North, Damnation and Yale have Low avalanche danger. Natural and human-triggered avalanches are unlikely. Evaluate snow and terrain carefully.

Tuckerman Ravine has MODERATE and LOW avalanche danger. Right Gully, Sluice, Lip, Center Bowl, Chute and Hillman’s have Moderate avalanche danger. Natural avalanches are unlikely and human-triggered avalanches are possible. Heightened avalanche conditions exist on specific terrain features. Lobster Claw and Left Gully have Low avalanche danger. Natural and human-triggered avalanches are unlikely. Watch for unstable snow on isolated terrain features.

AVALANCHE PROBLEM: Wind Slab will be the avalanche problem today. The primary concern will be soft slab formed by the 2” of snow on Saturday and 2.3” on Sunday. This snow also fell in our fetch (the Bigelow Lawn and Alpine Garden) and SW through WNW winds has transported a significant amount into the ravines. This slab appears smooth and may be quite deep in places like the approach to ice climbs. The other concern would be slabs that formed from Friday’s Nor’easter. That snow was subjected to strong winds that in places scoured the snow while in others left firm wind slab. Safe travel and constant reevaluation will be required to travel through terrain today.

WEATHER: Starting the New Year off on the right foot, it snowed yesterday. About 2.3” fell in the morning on 50-70mph W winds. With occasional gusts into 80 and 90mph range, winds shifted to the WNW and slowly calmed over the evening to the current 35mph. Winds will continue to decrease and shift to the SW. Coupled with clearing skies and temperatures rising into the 20sF, today looks like a brilliant day to be on the mountain. Tomorrow’s forecast is still up in the air. If it stays all snow, we could see up to 10”. However, it’s looking likely that we will see sleet and maybe even rain at some point.

SNOWPACK: Before the Nor’easter on Friday, a melt/freeze cycle created our base layer. Strong winds on Friday post-storm scoured areas like the upper northern gullies in Huntington and Left Gully. This same wind also created firm wind slab and sculpted snow in other locations. Snow on Saturday and Sunday has blown in on top of this and created 4F+/1F- slabs in areas like the fork in Hillmans, the Chute through the Sluice, and the mid-elevations of southern gullies in Huntington. This soft slab is my primary concern today. With snowfields having developed so rapidly over the past week, thin spots (created by recently buried rocks and terrain features as well as the edge of a newly formed slab) may be lurking where you may not suspect. Careful navigation and safe travel techniques will go a long way today.

The Lion Head Winter Route is open and the most direct route to the summit from the east side of the mountain. Please be on the lookout for machine traffic on the Sherburne as we remove construction debris over the coming week.

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 8:25a.m., Monday, January 2, 2017. A new advisory will be issued tomorrow.

Helon Hoffer, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2713

2017-1-2