Avalanche Advisory for March 1, 2018

Huntington and Tuckerman Ravine have LOW avalanche danger. Generally safe avalanche conditions exist. Watch for unstable snow on isolated terrain features. The Little Headwall is an open stream and is not rated.

AVALANCHE PROBLEM: Thin wind slabs, which formed earlier in the week, are scattered throughout northeast facing terrain. These have passed through their unstable phase and should not be of much concern except possibly in the very steepest locations. The old gray refrozen snowpack that makes up most of the travel surface in our forecast area, will be underfoot everywhere due to the thin coating of new snow on top. This surface will create the primary concern for climbing and riding due to its firm and icy nature. Any softening that occurs later in the day in the sun or with warming temperatures will likely be only at the surface. On days like today with temperatures around freezing, passing clouds can allow the snow to quickly refreeze and make arresting a fall difficult at best. Crampons, an ice axe and the ability to use them well will be useful to avoid a long sliding fall today. 

WEATHER: Warm and soggy conditions at Pinkham are kicking off another day of unseasonably warm weather. The temperature reached 41F (5C) yesterday at Hermit Lake before dipping back down to 28F (-2C) overnight. Currently the summit temperature is 22F, with 30F at Hermit Lake at 6:30 a.m. Thick fog currently cloaks the Ravines but will begin to clear with partly sunny and SW winds diminishing to 10-25 mph in the afternoon. The high temperature at the summit is forecast to be in the mid-20’s.

SNOWPACK: Last month, temperatures at the summit averaged 6.8 F above average. The 6.73” of SWE (snow water equivalent) that fell in February was close to average though warm spells allowed this precipitation to fall as rain, some of it heavy.  The summit received 51.6” of snow, which is about 12” above normal, but the snow took a beating by the warm temperatures and rain. Despite the warm temperatures, the ice has held up well in Huntington and the snowpack in Tuckerman seems set up for decent spring skiing, though the Lip has suffered from the large wet slab/waterfall blow out in January.

Fans of winter are no doubt keeping a close eye on the low pressure system moving across Pennsylvania on its way to Cape Cod. Though models are beginning to agree that the track will remain well south of the area, atmospheric conditions appear to be favorable for banding which may bring heavy snow to the Presidential Range. Snowfall totals will be variable by elevation but seems like there will be more than enough snow to bring elevated avalanche concerns tomorrow.  Saturday will likely have increased avalanche risks as well if wind wraps around to the west as it often does after a storm like this. Be sure to check the advisory before committing to your objectives over the weekend. 

The John Sherburne Ski Trail holds a wide variety of conditions, including exposed rocks, areas of water ice, which is sometimes thinly veiled covered with the new snow that fell earlier this week. Plenty of skiable snow remains but caution and careful turns are advised.

The Harvard Cabin will be open Thursday, Friday and Saturday night this week. 

Remember:
• 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 Harvard Cabin.
• Posted 8:00 a.m., Thursday, March 1, 2018. A new advisory will be issued tomorrow.

Frank Carus, Lead Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856

2018-03-01