Avalanche Advisory for Wednesday, December 14, 2016

Huntington Ravine has CONSIDERABLE and MODERATE avalanche danger. Central, Pinnacle, Odell and South Gullies have Considerable avalanche danger. Natural avalanches are possible and human-triggered avalanches are likely North, Damnation, Yale, and Escape Hatch have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. Evaluate snow and terrain features carefully.

All forecast areas in Tuckerman Ravine have CONSIDERABLE avalanche danger. Natural avalanches are possible and human-triggered avalanches are likely. The Lower Snowfields and Little Headwall are not rated due to lack of snow.

AVALANCHE PROBLEM: Today’s avalanche problem will be Wind Slab. This will exist throughout the forecast period as snow and wind loading continue. This also includes wind slabs that developed from Monday’s snow. There is potential to step down into this layer, creating the possibility of some of the larger avalanches we have seen yet this season. With blowing snow creating limited visibility, getting eyes on start zones may be tough today, making it harder to travel safely through avalanche terrain.

WEATHER: Tuesday began with strong west winds that gusted to 90mph in the pre-dawn hours. By the end of the day, wind speeds calmed to 30mph and shifted to the SW. During this period of SW winds, 2.8” of snow was recorded on the summit. Through the night, winds picked back up to a current 60mph from the west. Hermit Lake recorded just under 1” of snow at the snow plot this morning. Today, expect up to another 2” of snow delivered on 35-60mph west winds. Tonight, we are looking at another trace to 2” on west winds increasing to 75mph.

SNOWPACK: As we often see with strong winds, the two ravines act dramatically differently. Time in Tuckerman yesterday revealed numerous crown lines, including one that runs from under the choke of the Chute over through Center Bowl. This crown was already filling back in with blowing snow continuously coming down over the headwall. No crown was visible in Hillman’s Highway, but both start zones are well-filled in and debris from a slide rested below the dogleg near the bottom. We are now loading another almost 3” from last night with the potential for another 2” today onto this. Today will be a heads up day in Tuckerman with potential for avalanches to extend to the floor of the ravine. Keep in mind, once past Connection Cache on the Tuckerman Ravine Trail, you are in avalanche terrain.

Huntington was a different story yesterday. Winds scoured the northern gullies, leaving very little snow in place. The snowfield below the ice in Odell filled with debris from a slide likely overnight on Monday. South and Escape Hatch also grew substantially from Monday’s storm, with both start zones now becoming developed. The two areas of greatest hazard in Huntington looked to be the pillows below the ice in Central and Pinnacle, which were both smooth and now will grow larger with more snow today. I would expect today’s snow to bond better with the textured surface on the north wall than the smooth start zones of Escape Hatch through Central.

The Lion Head Summer Trail remains the better route to the summit. Remember that the bridge work continues on the Tuckerman Ravine Trail so use the detour on the Huntington Ravine Trail. Many people are using the Sherburne as an uphill route; please be on the lookout for these people as well as machinery that is using the Sherburne as the access to the construction site.

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 8:25 a.m., Wednesday, December 14, 2016. A new advisory will be issued tomorrow.

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

2016-12-14