Avalanche Advisory for Friday, 4-19-2013

This advisory expires at 12:00 midnight.

Tuckerman Ravine has LOW avalanche danger. Natural and human triggered avalanches are unlikely.

A General Advisory is currently issued for Huntington Ravine. We are done issuing daily avalanche forecasts for Huntington for the remainder of the season. You will need to do your own snow stability assessments when using avalanche terrain. A danger of falling ice exists and will persist until it all comes down.

Clearing but windy conditions will dominate the daylight hours with SW winds in the 55-75 mph (90-120 kph) range diminishing slightly in the early afternoon.  Gusty conditions through the day and possibly thunderstorms in the evening due to a cold front passing will challenge those camping or caught out late. Rain will accompany this cold front and may be heavy at times. Though recent warm weather with sporadic refreezing has yielded a snowpack resistant to avalanching, there are many other hazards to be aware of including the following:

  1. Factor the possibility of FALLING ICE into your travel plans. The annual process where all the ice that formed during the winter crashes down has begun. Rain and warm temperatures make the problem worse.  We know it will happen, the question is exactly when. Don’t fool yourself into thinking that you are faster than  chunks of ice sliding and bouncing erratically down the snow. Lunch Rocks and the floor of the ravines are directly in the path of falling ice. There have been many significant injuries, as well as at least one fatality, due to this hazard. Creative planning can keep you safer by giving ice fall runouts a wide berth. The waterfall at the Lip is now melted out and flowing a significant volume of water which creates a deep and dangerous slot.
  2. Stay clear of CREVASSES. We have yet to see much of this problem yet, but they have begun to form in the upper Lip area as well as a couple of other isolated locations. Warm temperatures will cause the snowpack to creep downslope, which opens up deep cracks in the snowpack. These grow large enough for a climber or skier to fall into, and often they can’t be seen from above. The best way to know about this hazard is to climb up your intended descent route. If you see cracks in the snow, stay well away from the edges. Be aware of slots opening at the bases of cliffs as well as beneath frozen waterfalls which will continue to run water due to rain and warm weather. Probing ledges of snow near rocks with your ski pole is often a good idea.
  3. Avoid UNDERMINED SNOW and the Little Headwall. Right now this issue is mostly found in the streambed leading out of the ravine and on the Little Headwall. The Little Headwall has a large open hole in the steepest part of the route.  This hole has grown in the last couple days, and is threatening to collapse further. The same can be said for the snow bridges in the streambed above the Little Headwall.  We don’t recommend skiing out from the bowl. Hiking out on the trail is a faster and safer option.

Tomorrow marks the day of the Inferno Race. Tomorrow’s weather will create a new set of hazards due to falling temperatures. Be sure to check weather forecasts at the Mount Washington Observatory and National Weather Service as well as our Weekend Advisory, which we will post later this afternoon, for further details. Remember that there are no facilities open on the summit and no other option for descent other than traveling under your own power.

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 at 8:00 a.m., April 19, 2013. A new advisory will be issued tomorrow.

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

2013-04-19 Print friendly