Posted 7:40a.m., Thursday, January 13, 2011
All forecast areas in Tuckerman and Huntington Ravines have CONSIDERABLE avalanche danger today. Natural avalanches are possible and human-triggered avalanches are likely.
The mountain has received a healthy serving of snow from the cold Nor’Easter that just rolled through town but it looks like all snowfall will wrap up by midday. The good news is that the Summit picked up 8.8” (22cm) of 5% snow by midnight last night and then almost another inch by 6 a.m. The better news is that the lower part of the mountain picked up even more! The Hermit Lake snowplot had 16″ (41cm) as of 6:30am. Winds performed as expected sliding from the E through the NE and N before wrapping around to their current location out of the WNW at 54mph (87kph). This allowed a combination of direct loading and cross-loading in most areas and when the clouds lift we expect to see evidence of the season’s biggest avalanche cycle. Avalanche activity in the week prior to this storm had filled in much of Tuckerman’s floor allowing subsequent avalanches to push farther more easily. Blowing snow will continue to make it hard to navigate this morning so you may not realize you’re in an avalanche runout path until it’s too late. We’ve just come down from High avalanche danger and are sitting in the upper end of the Considerable rating. Natural avalanche activity is a strong possibility in the earlier part of the day due to the ongoing loading and cross loading of numerous slopes.
I expect that when clearing occurs later today we’ll see a mixture of fracture lines, debris piles and wind-loaded slopes with reactivity to human triggers. As the wind dies down later in the day and blowing snow no longer fills the air the potential for natural activity will decrease and human triggered avalanches will become the primary concern. It is times like these that conservative decision-making is most important. Sunny skies and the lure of fresh tracks is a dangerous combination immediately following a wind and snow event.
The John Sherburne Ski Trail is thankful for the recent snow. Underneath the new blanket is a mixture of frozen crud, water ice, abrupt waterbars and bushy vegetation. Keep those tips up and watch for wind affected areas.
- 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.
Justin Preisendorfer, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856