Avalanche Advisory for Wednesday, 12-25-2013

Expires at 12:00 midnight Wednesday, December 25, 2013.

All forecast areas of Tuckerman and Huntington Ravines have Low avalanche danger today. Natural and human triggered avalanches are unlikely except in isolated terrain features.

AVALANCHE PROBLEM:  The existing snowpack is quite stable; very few avalanche problems currently exist on Mt. Washington. Other mountain hazards will play a far more prominent role in your travels. These include:

  • Generally icy trail conditions and breakable crust if you go off the beaten path. We highly recommend crampons and an ice axe for travel in steep terrain or other traction footwear for travel on hiking trails. Remember that the trails that pass through Tuckerman and Huntington ravines are buried under snow and ice, which makes them more of a mountaineering adventure than a casual hike.
  • Long sliding falls. In those locations where continuous snow coverage exists, the icy surface will make it difficult for you to stop yourself if you were to fall.
  • Ice dam formation. This is something that climbers in Huntington need to know about. As temperatures drop, drainage channels get plugged with ice, causing water pressure to build behind the ice. This can be annoying or it can be very dangerous, but you never know which until you release the pressure with your ice tool or crampon.

WEATHER: As mentioned, we had a long thaw and rain event last weekend. On Monday, temperatures fell back below the freezing point. So the mountain has now been below freezing for a couple days. On Monday night, we received 1.6″ of snow at the summit, but only found 1cm of snow at our study plots lower on the mountain. Today should be a pleasant day by Mt. Washington standards. There is some snow in the forecast for Thursday. At this time, 2-4″ are forecast.

SNOWPACK: Our snowpack took a beating from the rain. If you are looking for an interesting, layered snowpack, you’re unlikely to find it here. What you will find is a uniform layer of refrozen grains of snow, capped off with a freezing rain crust and a dusting of new snow. In some isolated terrain features, you may find deeper pockets of new windslab on top of this crust. After what I saw in the field yesterday, I don’t think many of these will be deep enough to be a problem, but if you should find a deeper one, there is a good chance it will be sensitive to triggering.

Current snow coverage is thin across the mountain. If you were to ask, I wouldn’t recommend coming up here just to ski the Sherburne. In fact, if you were already at Pinkham with skis on your pack, I’d actually try to dissuade you from bringing them up.

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 6:40 Wednesday, December 25, 2013.  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

2013-12-25 print friendly