This avalanche advisory expires at midnight Saturday, 2-25-2012
All forecast areas of Tuckerman and Huntington Ravines have HIGH avalanche danger. Natural avalanches are likely and human triggered avalanches are very likely. Travel in avalanche terrain is not recommended. This forecast also includes the Lower Snowfields, which are posted at High danger, and the Little Headwall, which is posted at Considerable danger today.
Well, it’s actually happened. We got a real, bona-fide snowstorm last night. That makes me wish I could call in sick and go ski the Mt. Washington Valley Chocolate Festival tour, but I’ll settle for working on Mt. Washington as a consolation. Since it began, the summit has recorded 6.3” of 10% density snow. It seems like we have a little more than that down here at Hermit Lake, but our snowplots were affected by wind so the data is a little off. I’d estimate about 8” has fallen. Down at Pinkham Notch we measured 7”. An additional 1-2” is forecasted to fall during the day. Looking at the higher summits wind forecast, the avalanche hazard becomes pretty clear to us: we expect to have avalanche activity in numerous locations, perhaps some even sliding multiple times throughout this event. The higher density snow and wind velocities lead me to believe we could see some large hard slab avalanches. These are not the soft fluffy kind you see in the ski movies; they’re the kind that can snap trees like matchsticks and they can travel farther into the runouts than previous slides have this season. We do not recommend traveling into avalanche terrain today, even just to the floor of Tuckerman or into the fan area of Huntington.
Travel above treeline this weekend will be challenging, to say the least. As the weather system progresses, WNW winds will ramp up to speeds easily gusting in excess of 100mph. You’ll be in the clouds starting well below treeline, and blowing snow will significantly hamper your visibility as you attain treeline. In addition to low visibility and strong winds, temperatures will be falling through the day to an overnight low of -10F. If you want to venture up high, do so with a willingness to turn around and head downhill when needed.
You may have noticed that we began forecasting the Lower Snowfields and the Little Headwall today. The Lower Snowfields will likely have avalanche activity coming into it from the Duchess and Dead End Gully above, but could also have avalanche activity from within the snowfields themselves. The Little Headwall holds the lowest stability hazard for today. Strong winds are ideal for loading slabs into this area, and we certainly have those today. Should you be unfortunate enough to be caught even in a small slide, there is a chance you’d end up in an open hole in the river. Tomorrow, clouds and snow will clear out, but the winds will remain very strong and temperatures cold. I would expect that most of the forecast areas rating will decrease. Some, such as in Huntington, may even go down to Low danger due to avalanches and wind-scouring. Other areas may go down to Considerable or Moderate. Be sure to check the advisory tomorrow morning, and equally important, check the weather forecast before heading out.
- 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 8:35am. 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