Avalanche Advisory for Friday, February 17, 2017

This advisory expires at Midnight.

Huntington Ravine has MODERATE avalanche danger today. All forecast areas in Huntington Ravine have Moderate avalanche danger. Natural avalanches are unlikely and human-triggered avalanches are possible. Heightened avalanche conditions exist on specific terrain features. Evaluate snow and terrain carefully to identify features concern.

Tuckerman Ravine has CONSIDERABLE and MODERATE avalanche danger today. Sluice, Lip, Center Bowl, and Chute have Considerable avalanche danger. Natural avalanches are possible and human-triggered avalanches are likely. Careful snowpack evaluation and cautious route-finding is essential. Lobster Claw, Right Gully, Left Gully, Hillman’s Highway, Lower Snowfields and Little Headwall have Moderate avalanche danger. Natural avalanches are unlikely and human-triggered avalanches are possible.  Evaluate snow and terrain carefully.

AVALANCHE PROBLEM: Wind slabs that developed overnight are continuing to build but to a more limited degree as wind abates and available snow is depleted. Beware of smooth areas of wind slab, even in moderate rated areas. In these locations, wind slabs are likely to be firm and somewhat stubborn but also potentially large so enter any avalanche terrain cautiously today. Considerable rated areas continuing to be loaded at greater rate and contain larger areas of wind slab.

WEATHER: Winds are currently blowing from the NW at 68mph on the summit. Wind will remain generally from the NW and gradually diminish through the day, though the currently limited wind transport of snow into avalanche start zones will continue. The temperature at the summit will rise from where it sits at 5F to the teens F. The summit recorded around 5” of snow in the past 24 hours and around 22” since February 15. Total snowfall recorded on the summit this month is 68” with 94” at the snow stake on the snow study plot at Hermit Lake.

SNOWPACK: Avalanche activity yesterday and overnight has once again altered the lay of the land in our forecast area. Northwest winds seemed slow to ramp up yesterday but clear signs of rapid wind loading were obvious from my vantage point in the afternoon from Wildcat. A wide crown exists in the Center Bowl and Lip area, the upper start zone of the Lip, near the Chute, and in Duchess. Most of these crown lines are reloaded making it pretty clear that reloading occurred mid avalanche cycle. A mix of heavily textured sastrugi as well as large smooth pillows and even some older ice crust exists in various amounts through the terrain depending on aspect and exposure. Northern gullies in Huntington are mostly scoured and wind hammered though the approach from the Fan is large and smooth and is probably best avoided. Similarly, Lip, Center Bowl over through the Chute have been reloaded are seem somewhat ripe for an avalanche. Crossloaded areas in the upper right of Hillmans are a concern though sastrugi dominates the surface mid-slope.

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., Friday, February 17, 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