Posted 7:30, Wednesday, January 05, 2011
Tuckerman and Huntington Ravines have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanche are possible. The Escape Hatch, Lower Snowfields and Little Headwall remain not posted due to a lack of snow in these areas.
DON’T FALL ASLEEP OUT THERE! If you have been following our advisories you know that the majority of our existing snowpack is rock solid and digging a pit into this mass would require tools not typically found in a snow geek’s quiver (i.e., chainsaw). It would be easy to glance over the subtle details of recent weather observations and ignore snow stability as a concern all together. I urge you to pay attention to the details and venture out there with a well informed level of caution. Over the past two days the summit has recorded 2.8” (7 cm) of light density new snow. Hermit Lake picked up 2.6” (6.5 cm) of 5% snow since yesterday morning. Winds have been primarily out of the W and are forecasted to be out of the NW today with speeds between 45 and 60 mph (72 to 96 kph) with higher gusts. The light snow accumulations paired with recent and forecasted wind speed and direction makes me think there is new wind slab out there clinging to an icy bed surface. While the recent snow totals are lean, Mt. Washington’s wind does an outstanding job at putting it where it counts; into the Ravines. Upslope conditions are forecasted to bring scattered snow showers to the mountains today which grabs my attention even more. In the past I have seen this type of forecast produce a trace of snow and I have seen it dump over a foot of light density powder. Unfortunately, I don’t think conditions are right for the surprise foot of snow but you do need to pay close attention to how much is accumulating on the mountain today. Expect increasing avalanche danger with each additional inch of snow because whatever falls will be transported into avalanche terrain and made into wind slab in lee areas. While all forecast areas have the potential to harbor new wind slab, I am particularly concerned about Tuckerman Ravine from Left Gully through Right Gully. With the recent west winds grabbing snow deposited on Bigelow Lawn, a large flat area directly above and to the west of Tuckerman Ravine, I think these forecast areas will have more stability issues than others.
Snow won’t be the only thing trying to cling to an icy surface today. Anyone venturing onto the mountain needs to be ready with good traction from the base of the mountain to the Summit. Long sliding falls are a real potential in steep terrain and in places on the Tuckerman Ravine trail below Hermit Lake. Crampons or similar gear are a must right now and solid self arrest skills are critical for anyone venturing into the steeps. I am sorry to report that the Sherburne Ski Trail is bad. I don’t usually make such blunt statements about conditions because we all have our own opinions about how much fun ice and grass can be but it really is bad right now. Water ice, frozen snow and long melted out sections and a dusting of snow to hide all of these surprises will greet any adventurer who wants to try.
- 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.
- This advisory expires at midnight. A new advisory will be issued tomorrow.
Brian Johnston, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856