Avalanche Advisory for Sunday, January 15, 2017

This advisory expires at midnight.

 

Tuckerman and Huntington Ravine have LOW avalanche danger. All forecast areas have Low avalanche danger. Natural and human-triggered avalanches are unlikely. Watch for unstable snow on isolated terrain features. In Tuckerman Ravine, Lower Snowfields and Little Headwall are not rated due to thin snow cover.

AVALANCHE PROBLEM: Thin Wind Slab will form today in isolated pockets. While likely small in size, scattered, and easy to identify when compared to the old surface, they could be enough to knock someone off their feet, leading to the big hazard today: long, sliding falls. With a firm snowpack underfoot, the use of crampons and ice axes will be necessary today. Self-arresting will be nearly impossible once a falling object gains speed, so careful travel is advised today. Glissading with such firm conditions more often leads to an out-of-control slide and problems, rather than to a controlled descent.

WEATHER: Temperatures remained near the zero degree Fahrenheit mark yesterday and overnight with west winds gusting to the high 80mph range early this morning. A trace of snow fell at Hermit Lake this morning with the summit receiving 0.6” so far. Clouds will linger for the morning, possibly bringing another trace of snow, with skies clearing as the day progresses. Northwest winds are currently blowing 80mph and will decrease to around 45mph by dark. Skies will remain clear tonight with west winds as low as 30mph.

SNOWPACK: Rain and warm temperatures last Thursday created widespread, hard snow surface. This surface requires the use of crampons above treeline and perhaps roping up on the approach to your intended climb. Under an inch of snow in the early morning arrived on strong NW winds. While most areas will be scoured clean of this new snow due to strong winds, terrain features will allow pockets of wind slab to grow in certain lee areas. These should be easily recognizable as they will be softer snow than the hard surface in other locales. Be prepared to navigate these pockets, particularly at the base of ice climbs in Huntington.

A busy holiday weekend will lead to many people on the mountain today. In addition to keeping an eye on yourself and your partner, beware that there could be a large group above and below you. Bottlenecking on a day like today can easily happen, and one person slipping and falling can create the domino effect on those below. Be prepared for routes to be crowded and to have to decide whether to wait in line or choose a different goal for the day.

The Lion Head Winter Route is the most direct route to the summit on the east side of the mountain. Please be on the lookout for machine traffic on the Sherburne ski trail.

Please 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 the Harvard Cabin.
  • Posted 7:45a.m., Sunday, January 15, 2017. A new advisory will be issued tomorrow.

Helon Hoffer, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2713

2017-01-15