Tuckerman Ravine has Considerable and Moderate avalanche danger today. The Sluice, Lip, Center Bowl, and Chute have Considerable avalanche danger. Natural avalanches are possible and human triggered avalanches are likely. Lobster Claw, Right Gully, Left Gully, and Hillman’s Highway have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. The Lower Snowfields and Little Headwall have Low avalanche danger. Natural and human triggered avalanches are unlikely.
Huntington Ravine has Moderate and Low avalanche danger. North, Damnation, and Yale gullies have Low avalanche danger. Natural and human triggered avalanches are unlikely. Watch for unstable snow on isolated terrain features. All other forecast areas of Huntington have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible.
For the next couple days, this might be the last morning where we arrive at Hermit Lake with fresh snow on the ground. 5cm of light density snow was measured at our snowplot this morning. That’s just shy of 2” for metric-phobes, and it brings the summit totals to around 8” (20cm) in the last four days. This new snow, coupled with steady NW and W winds, is contributing to the avalanche danger ratings being exactly the same as yesterday. The primary avalanche concerns today are fresh windslabs and will most easily be found in the middle of Tuckerman, especially the Lip and Center Bowl areas. These locations have a tendency to avalanche more frequently than other areas, and I think today is no exception. Expect E and SE aspects in other gullies to also have received some new loading. Examples include the tops of Right Gully and Lobster Claw in Tuckerman and Pinnacle, Central, and Yale in Huntington. Yale, along with Damnation and North, is rated Low, but you should still be wary of unstable snow on some terrain features.
The high pressure system that will dominate our weather in the coming days is just now beginning to clear clouds out of the ravines. This will make it easier for you to make your travel decisions without wondering what might be going on up above you. In both ravines I think you’ll see a variety of surfaces. You’ll see dense hard slab that has a lot of strength, sitting right beside softer snow in more protected locations. Things you might see to indicate unstable snow include soft creamy-looking areas of freshly loaded slabs, or recent crown lines or debris piles on nearby slopes. Hard old surfaces that had been wind scoured would indicate greater stability. Whenever possible, traveling on very firm snow will decrease your chances of triggering an avalanche. Overall, conditions are still thin and rocky, so the consequences of even a small avalanche can be significant.
We have opened the Lion Head Winter Route for the season. This is a steep mountaineering route, and we strongly recommend bringing an ice axe, crampons, and the ability to effectively use these tools.
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 8:35am, Friday January 7, 2013. A new advisory will be issued tomorrow.
Jeff Lane, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856