A new advisory will be issued when conditions warrant or within 72 hours. Unless updated this advisory expires at 12:00 midnight, Wednesday January 4, 2012
This is an early season GENERAL AVALANCHE ADVISORY for Tuckerman and Huntington Ravines. General Advisories are issued when isolated instabilities may exist within the forecast areas. Forecasts using the 5-scale danger rating system will begin when snowfields and bed surfaces become more developed. Please remember that avalanche activity may occur before the issuance of a 5-scale danger rating forecast. You will need to make your own snow stability assessments when traveling in avalanche terrain. In Tuckerman and Huntington Ravines there are isolated snowfields that are growing in size and may harbor instabilities.
Happy New Year! With each passing weather event we are inching closer to the usual and customary winter conditions. An additional 3” (7.5cm) of snow fell at Hermit Lake last night and more accumulating snow is expected by the end of the day Tuesday. Much of this will be enhanced by upslope effect, which looks promising but is certainly not guaranteed to leave much on the ground. The big weather story for the next couple of days will be arctic temperatures. A cold air mass from Canada will be pushing through, bringing very cold temperatures to the mountains.
Snow stability concerns are currently limited to the isolated snowfields in each ravine. Although we consider these snowfields to be isolated, this does not mean avalanche activity cannot occur. Any location where new snow can be loaded onto a potential bed surface can develop unstable snow. The largest of these bed surfaces can currently be found in Left Gully and the Chute area of Tuckerman and Central and Odell Gullies in Huntington. Other smaller snowfields can also be found, such as in the Center Bowl and Sluice or in Pinnacle or Yale. These are only examples. Spatial variability is incredibly strong in these early season conditions. Be on your toes since conditions will change as you move from one snowfield to another.
Aside from stability issues, ice dams may become problematic for climbers as the temperatures plummet. Currently there is a lot of ground water moving behind the ice, so when the drainage channels become choked off with new ice a lot of hydraulic pressure can build.
For those interested in knowing, the Sherburne has been getting ski traffic. We can’t say whether or not the skiers have actually enjoyed it, but they have been able to make it to the bottom. There is definitely more snow on the ground at Hermit Lake than at Pinkham, so expect more open water and exposed ice as you descend.
- 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 9:15 a.m., Monday January 2, 2012. A new advisory will be issued when conditions warrant.
Jeff Lane, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856