Avalanche Advisory for Friday, December 15, 2017

Huntington Ravine has MODERATE and LOW avalanche danger. Central, Pinnacle, Odell, South and Escape Hatch have Moderate avalanche danger. Natural avalanches are unlikely and human-triggered avalanches are possible. North, Damnation and Yale Gullies have Low avalanche danger. Natural and human-triggered avalanches are unlikely. Evaluate snow and terrain carefully.

Tuckerman Ravine has MODERATE and LOW 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. Evaluate snow and terrain carefully.

AVALANCHE PROBLEM: Wind Slab will be our primary avalanche problem today. High wind continued to move a bit of snow around yesterday and last night further loading existing slabs and reloading paths that avalanched on Tuesday and Wednesday. It is likely that most of these slabs will be stubborn but keep your guard up if you are venturing into steep terrain. Continued cold temperatures aren’t helping stability improve and it may even be worth considering early facet development deeper in the snowpack. Avoid or stay above smooth areas of wind slab and consider your runout. Even a small avalanche could surprise you or sweep you off of your feet.

WEATHER: Temperatures on the summit have rebounded from -17F last night to -8F at 7am. This trend should continue today, bringing the high just above 0F. Moderating wind and clear skies will make for reasonable, though still quite cold, travel conditions. Expect westerly wind to diminish from the 60-mph range to the 20-30 mph range through the day. A trough will be the dominant feature for the next few days, allowing weak disturbances to pass through the region. An inch or so could fall Saturday, with reduced visibility and continued cold. Be sure to check the current NWS and MWObs forecast when making plans and be prepared to navigate with few tracks to follow and low visibility above treeline.

SNOWPACK: Old man winter seems to have fully moved into the mountains instead of the brief earlier visits. Our snowpack has grown quite a bit with the recent storms and subsequent avalanche activity. We still need a couple more storms to fully flesh out the trails and avalanche paths but conditions are looking up for sure. Ice climbs are growing again and approaches are getting easier. As stated several times, stay vigilant when micro-route finding through the terrain. Any sliding fall or avalanche would have pretty significant consequences given the many exposed cliffs, boulders and terrain traps throughout the terrain. Check our Instagram link for photos. We’ll post some from Huntington Ravine later.

The summer Lion Head Trail is the safer route to the summit than trails through Tuckerman and Huntington. The Lion Head Winter Route will open when snow fills in avalanche paths on the summer trail and fills in the winter route enough to cover rocks, mud and bushes. The John Sherburne Ski Trail has improved but there are still rocks and wind scoured bare areas. High wind has drifted dense snow in areas with generally challenging ski conditions prevailing.

Please Remember:
• Safe travel in avalanche terrain requires training and experience. This bulletin 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 8:05 a.m., Friday, December 15, 2017. A new Advisory will be issued tomorrow.

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

2017-12-15