This advisory expires tonight at 12:00 midnight.
Tuckerman Ravine has CONSIDERABLE and MODERATE avalanche danger. The Sluice, Lip, Center Bowl, Chute and Left Gully have Considerable avalanche danger. Natural avalanches are possible and human triggered avalanches are likely. Careful snowpack evaluation, cautious route-finding and conservative decision making are essential. All other forecast areas have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible.
Huntington Ravine has CONSIDERABLE and MODERATE avalanche danger. Central, Pinnacle, and Odell Gullies have Considerable avalanche danger. Natural avalanches are possible and human triggered avalanches are likely. Careful snowpack evaluation, cautious route-finding and conservative decision making are essential. All other forecast areas have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible.
AVALANCHE PROBLEM: Wind slab is our primary avalanche concern again today. New snow and increasing wind speeds yesterday created hard wind slab in many areas. Where these wind slabs exist, they are likely to be hard, fairly thick and capable of propagating a crack on a slope above you. In other areas more sheltered from the strongest NW winds, softer Storm Slabs mixed with the wind slabs may also present a problem. Travel very carefully to avoid these unstable slabs as well as the paths and terrain traps beneath them.
Both Ravines are still encapsulated in clouds so we are unable to verify where avalanche activity occurred or what forecast areas received more snow than others. However, historically the locations posted at Considerable today receive the most volume, harbor higher slab instabilities, and require more caution from weather events similar to the last 48 hours. We expect clouds to begin clearing soon allowing us to get into the terrain for new data collection that will get posted in the Weekend Update late in the afternoon. In the mean time expect cold slabs to be unstable and hold the ability to propagate a fracture. With bluebird days approaching with light winds watch yourself and the heuristic traps we can fall into when we are basking in what appears to be an “unbelievably awesome” day. Anticipate lingering instability in the high mountains this weekend.
- 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 7:50 a.m. December 19, 2014. A new advisory will be issued tomorrow.
Frank Carus/Christopher Joosen, Snow Rangers
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856