Avalanche Advisory for Sunday, February 15, 2015

This advisory expires tonight at 12:00 midnight.

Tuckerman Ravine has HIGH and CONSIDERABLE avalanche danger. The Sluice, Lip, and Center Bowl have High avalanche danger today. Very dangerous avalanche conditions exist. Natural avalanches are likely and human-triggered avalanches are very likely. Travel in avalanche terrain is not recommended.

All other forecast areas of Tuckerman and Huntington Ravines have Considerable avalanche danger. Natural avalanches are possible and human-triggered avalanches are likely. The Little Headwall has Moderate avalanche danger. Natural avalanches are unlikely and human-triggered avalanches are possible.

AVALANCHE PROBLEM: The avalanche problem you’ll be dealing with today is wind slab, though I encourage you to give your attention to the weather forecast for today as a significant problem you’ll need to be ready for if you’re out on the mountain. See below for details on the weather. The development of wind slabs will be most intensely focused on wind-sheltered SE-facing slopes such as the Lip and Sluice in Tuckerman. Slopes adjacent to these will also be on the receiving end of wind-transported snow and have a significant avalanche hazard. Travel into avalanche terrain, particularly the floor of Tuckerman, is not recommended due to the potential for naturally-triggered avalanches to extend into flat terrain. You don’t need to be on steep slopes to be at risk of avalanches today!

WEATHER: Mt. Washington will truly be putting on a show today and tomorrow. Its well-earned reputation for harsh winter weather will be on display, and I’d recommend taking a seat away from the action for this show. We only received a few inches of 10% snow from yesterday’s storm. Honestly, it was quite a disappointment. If we’re lucky we might get 1-2” (2.5-5cm) more during the morning hours, but any lingering snow showers will have wrapped up by afternoon. Temperatures will be falling today, reaching -35F (-37C) on the summit overnight.  During this time, wind speeds will be rising quickly up to the 100mph (161kph) mark with gusts possibly reaching 125mph (201kph). These conditions are not to be taken lightly. I encourage you to be judicious in your choice of adventure today. Even if your plan is to stay well below treeline today, bring plenty of warm clothes and extra food and water.

SNOWPACK: We’re not likely to be out in the ravines digging into the snowpack today, and you don’t need to be to understand the avalanche problem. Even though the storm was a letdown, there are still a few inches of new snow around the mountain, a little more possible today, and ample amounts of snow sitting around both above and below treeline. All this will be available to very strong NW winds for redistribution into the ravines. I expect to see the greatest loading rates and largest slab development in the strongly protected slopes in Tuckerman. Also, smaller terrain features may protect slopes enough to allow for slab development as well, regardless of whether it’s in the direct lee of prevailing NW winds. You should expect increasing avalanche danger today, with some areas rising up beyond the Considerable rating. Wind speeds that we are expecting can push slabs down lower into the ravines than you might think, so don’t be surprised to find unstable snow in areas such as the Lower Snowfields, Little Headwall, or the Fan in Huntington.

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. February 15, 2015. 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