Avalanche Advisory for Monday, April 4, 2016

Tuckerman Ravine has LOW avalanche danger. All forecast areas in Tuckerman Ravine have Low avalanche danger. Natural and human triggered-avalanches are unlikely. Watch for unstable snow on isolated terrain features.

Huntington Ravine is under a General Bulletin. You will need to do your own snow stability assessments when traveling in avalanche terrain in Huntington. A danger of falling ice exists, and will persist until it all comes down.

AVALANCHE PROBLEM: Hard, icy snow surfaces dominate the terrain but firm wind slabs lurk in lee areas of a west wind from the 3”+ of snowfall over the past 36 hours. These wind slabs were built by high winds in the 70mph range and though they will be stubborn, they could fail in the steepest terrain. New snow falling today on diminishing wind speeds is unlikely to produce significant stability issues unless totals exceed forecast amounts. The new snow will make visual assessment and route-finding around unstable pockets of wind slab more challenging.

WEATHER: Winter has returned to the mountain with temperatures well below normal for this time of year. Unfortunately for snow sports enthusiasts, the latest low pressure system to pass through the region is once again missing us. We may receive up to two inches today, an amount which may freshen things up a bit but which is far below the amount needed to bring us back to normal snowfall levels. Expect another frigid day on the hill with a high temperature reaching to 6F from the current -6F on the summit. Winds will diminish from the 40 mph range and shift to the northwest from the west, ultimately blowing in the 10-25mph range on the summit.

SNOWPACK: Spatial variability will be the name of the game today. Those venturing into avalanche terrain will find a mixture of wind-scoured rain crust and firm, textured wind slab of varying thicknesses, all composed from snow and strong winds since Saturday evening. Slopes scoured by these winds will be penetrable only by crampons and an ice axe and be nearly impossible to self-arrest on. Areas that were not scoured likely contain firm wind slab that will be stubborn to trigger. The problem area for these wind slabs is often on its edge. As the slab thins, it may be possible for a human’s weight to affect a weakness in the slab. Beware of the transitions when moving from old surface to the pockets of wind slab.

The Sherburne Ski Trail is now closed at #7, allowing about 2/3 mile of skiing from Hermit Lake. Expect ice with a dusting of new snow. The Harvard Cabin is closed for the season. The only camping permitted in the Cutler Drainage will be at Hermit Lake Shelters.

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.
  • Posted 7:40 a.m., Monday, April 4, 2016. A new advisory will be issued tomorrow.

Frank Carus and Helon Hoffer, Snow Rangers
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2716

2016-04-04