Avalanche Advisory for Sunday, 1-15-2012

Tuckerman Ravine has Moderate and Low avalanche danger today. The Sluice, Lip, Center Bowl, and Chute have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. Right Gully, Left Gully, and Hillman’s Highway have Low avalanche danger. Natural and human triggered avalanches are unlikely The Lobster Claw, the Lower Snowfields, and the Little Headwall are not posted due to an overall lack of snow. Forecasts for these locations will begin when conditions warrant.

Huntington Ravine has Moderate and Low avalanche danger today. Central and Pinnacle 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.

It’ll be a cold clear day on Mt. Washington; Canadian high pressure is the reason. Expect very cold temperatures with increasing wind speeds in the afternoon. With these conditions, snow stability today will remain static. I don’t expect conditions to change much during the day, for the better or the worse. What we have for stability concerns are leftover from the 9.4” that fell on the mountain Thursday and Friday and the strong winds that followed. The wind loading during this event caused numerous avalanches around the mountain and left behind a mix of conditions. Within each area rated Moderate today there are specific terrain features where a person might trigger an avalanche. These are the in strongly protected lee areas, such as under the ice in the Center Bowl, in the Lip, and under the ice in the Sluice. Some of the areas of greatest concern generally follow the path of the Tuckerman Ravine summer hiking trail. This goes up above Lunch Rocks to the Sluice and then traverses high across the Lip area. I’d also include the lower part of the Lip and across into the Bowl, as well as pockets of loaded snow in the mouth of Right Gully and in the skiers’ left side of Left Gully. In all these areas, the weak layer to worry about will be one of the many interfaces between different layers of windslab.

In Huntington much of the terrain got pounded pretty hard by the 100mph+ winds on Friday night. Clearing skies yesterday afternoon allowed us good views into the ravine, and we saw a mix of blowing snow, fractures, debris, and wind-hammered snow. Central and Pinnacle were the two gullies that refused to give reason to drop their ratings to Low. Central has significant wind loading up against the rock on the climbers’ left side. In Pinnacle I’d be most cautious with the approach to the ice, since strong winds tend to push the snow down toward the base.

As always on busy holiday weekend, there are a lot of potential human triggers running around the mountain. Pay attention to what others are doing and don’t assume that they truly know what they’re doing. If you’re interested in what we’ve seen for avalanche activity, check our Facebook page later today. I’ll try to post up a summary soon.

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 8:20am. 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

2012-01-15 Print Friendly