Avalanche Advisory for Friday, January 13, 2017

This advisory expires at Midnight.

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. Lower Snowfields and Little Headwall are not rated due to thin snow cover.

 Huntington Ravines has LOW avalanche danger. All forecast areas will have Low avalanche danger today. Natural avalanches and human-triggered avalanches are unlikely.

AVALANCHE PROBLEM: Wind slabs building in the sheltered lee areas of strong west may be a problem today. The slabs may develop in wind protected areas of the strong northwest and west winds. These slabs will be small but, as history has shown, small avalanches in 45-50 degree terrain are not always harmless. It is likely that our actual avalanche hazard is on the low side of Moderate but visual assessment and digging will be needed to confirm. Wet slab concerns are rapidly diminishing as cold temperatures penetrate the snowpack and refreeze any remaining moisture from rain fall over the past 30 hours. That said, flowing water has sometimes resulted in delayed action avalanches as below-surface water channels change course so don’t assume a benign snowpack.

WEATHER: Last night’s cold frontal passage brings upslope snow showers, high winds and plummeting temperatures today. Gusty, west winds will shift to the northwest and blow in the 70-90 mph range. Currently, heavily rimed snow and graupel plus dense summit fog are challenging visibility. Clearing cloud cover will improve visibility through the day, though gusty strong wind will make for challenging, above-treeline travel conditions. The temperature on the summit is currently 16 F but will drop through the day reaching lower single digits by sundown and -15F by sunup tomorrow.

SNOWPACK: Add another crust to your mental map of the snowpack following yesterday’s .69” of rain. Firm surface conditions will ultimately prevail in most steep areas later today and through the weekend but expect to posthole until the cold reaches down into the snowpack. Good cramponing and icy skiing conditions will be the result of our latest thaw this season. Though limited visibility this morning is preventing observations in the forecast areas, anticipate some damage to ice climbs Huntington in the form of thin spots and ice dams. Pockets of new snow may conceal these hazards until your cramponed foot or pick announces their presence. A high temperature of 46 degrees at Hermit Lake and 14 cm of settlement tells me that lots has changed in Tuckerman. Previously existing layers of facets near the upper crusts were most likely steamrolled by the warm temperatures and moisture in most areas. In all likelihood, dry snow exists a half meter or so down despite the nearly ¾” of moisture. Remarkably little ice or exposed water bars exist on the Sherburne ski trail so good skiing conditions should return with the next snowfall. Unfortunately, there is no significant snow in the forecast so seems like a good time to go climbing and hiking.

The Lion Head Winter Route is open and the most direct route to the summit. Please be careful of bridge construction debris near crossover 7 on the Sherburne Trail when skiing or riding.

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 8:00a.m., Friday, January 13, 2017. A new advisory will be issued tomorrow.

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

2017-01-13