Avalanche Advisory for Thursday, March 2, 2017

This advisory expires at Midnight.

Huntington Ravine has MODERATE and LOW avalanche danger. Central and Odell Gully have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. All other forecast areas will have Low avalanche danger with natural and human-triggered avalanches unlikely.

 Tuckerman Ravine has MODERATE and LOW avalanche danger. Sluice, Lip, Center Bowl and Chute have Moderate avalanche danger. Natural avalanches are unlikely and human-triggered avalanches are possible. All other forecast areas have Low avalanche danger. Natural and human-triggered avalanches are unlikely. The Little Headwall is not forecast due to lack of snow. Skiing or riding from the Bowl is challenging now.

 AVALANCHE PROBLEM: Lingering moisture in the atmosphere is bringing moderate snowfall to Hermit Lake this morning. This snow is likely to bond well to the old snow surface but weather changes today will create suspect layers in this new snow. Currently, high west winds are transporting snow into lee terrain. This wind will increase and shift to the northwest today, continuing to load mid-slope start zones and cross load others. Anticipate elevated danger from new wind slabs today especially if we meet or exceed the forecast snowfall totals.

WEATHER: A little over a third of an inch of rain fell on the summit yesterday before changing over and dropping a half inch of snow early this morning. Summit temperatures finally dropped below freezing shortly after midnight last night bringing the latest thaw to an end. Upslope snowfall will continue through the morning and we appear to be on track to receive the 1-3” amount that is forecast. A one-two punch of cold fronts will lead to a very cold and windy weekend. The first cold front will arrive today on a tight pressure gradient generating NW winds in the 100+mph range. Summit temperature is currently 16F and will fall to near 0F by dark and continue to fall overnight, reaching-10F tomorrow morning. Saturday morning’s low temperature could set a record.

OTHER HAZARDS: With the recent warm spell continuing to work on the snowpack, springtime hazards have emerged early this year. Falling temperatures last night will make long, sliding falls possible again today as surface snow begins to refreeze. Be aware of the following other hazards today:

  • Ice dams – water flowing down Huntington gullies can build up pressure behind ice and burst from the force of an ice tool placement. This effect can be especially pronounced after a rapid swing in temperatures such as we have today.
  • Glide cracks, moats and crevasses have opened in places and may now be concealed with new snow, making identifying these extra difficult.
  • Undermined snow over stream channels can be a problem in gullies but more of a danger lower in the tributaries. The recent warmth and rain has streams flowing at a pretty good clip. Falling into one, especially with skis or board strapped on, can be disastrous.

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  8:15 a.m., Thursday, March 2, 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

2017-03-02