Avalanche Advisory for Tuckerman and Huntington Ravines

Posted 8:30a.m., Friday, February 11, 2011

All forecast areas of Tuckerman 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 areas of concern.

Huntington Ravine has Moderate and Low avalanche danger. South Gully and the Escape Hatch have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. All other forecast areas of Huntington have Low avalanche danger. Natural and human triggered avalanches are unlikely. Watch for unstable snow on isolated terrain features.

After a rather active start to the month, we’ve entered a bit of a lull lately. Almost 25″ (63cm) of snow fell on the Summit in the first 8 days. Over the last couple days nothing has been recorded on the Summit and only a couple of traces have fallen lower on the mountain. However, the infamous Mt. Washington winds have done their part to keep the avalanche conditions interesting. Tuesday night winds hit their peak with a gust from the W clocking in at 104mph (168kph). Since then they’ve stayed strong and have been able to sporadically inspire bursts of windloading, such as the banner that could be seen flying over Hillman’s Highway yesterday while winds were sustained in the 50-60mph range (80-97kph). Today the winds are expected to dip below where they’ve been for the past couple days, which will further reduce any active windloading. Conditions will remain fairly static as the cold weather helps to keep things where they’re at for the time being. I would expect to find a mixture of slab hardnesses out there, with everything from steel slab leftover from the 100mph winds to the relatively softer 1-finger slabs in more protected lee areas. Winds over the past few days have been predominantly from the W through the NW, so direct E and SE aspects would be the most in the lee. Examples include under the ice in the Center Bowl, in the Lip and Sluice, and the climber’s right side of Hillman’s Highway. Keep in mind that our snowfields have been maturing quickly in the past couple weeks and they are becoming increasingly connected to one another.

Huntington Ravine took more of a beating from the winds than did Tuckerman. The areas of most concern are in the start zones of the Escape Hatch and South Gully. The snow in these areas were protected more from the full force of the winds, allowing them to develop softer, more evenly distributed slabs. Elsewhere in the Low rated areas, you’ll want to watch out for unstable snow in the wind-protected areas below the rock buttresses on the approaches to the climbs and in areas like the midsection of Yale Gully.

Look for a Weekend Update coming later this afternoon or early evening. We’ll give our thoughts for next couple days including what’s in store for snow later this weekend (but don’t get too excited for that part).

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.
  • This advisory expires at midnight. A new advisory will be issued tomorrow.

Jeff Lane, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713  TTY (603) 466-2856

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