Avalanche Advisory for Sunday, 4-21-2013

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.

Your best bet for finding good quality snow to ski or ride today will be to postpone your trip for a day. OK, I understand that’s not always possible, so if you’re reading this at one of the posting sites on the mountain, keep reading to get a sense of what you’ll be facing today. The forecast for Monday is looking pretty good, so if you have the opportunity to put it off a day, you will see better conditions.

Current conditions this morning in Tuckerman are very slick and icy. Yesterday I watched skiers and riders struggle to get there edges to bite into the rain crust. Even in lower-angled terrain, many of these people failed at this and ended up sliding to the bottom of the bowl. Thankfully only a few were injured. In large part I believe this is because people recognized the problem and chose not to climb very far up the slope. Since the snow surfaces have only frozen harder overnight, taking the conservative approach is a good idea for today. Falling in steep terrain today will result in rapid acceleration unless you arrest your fall immediately. You can improve your odds by using an ice axe and crampons, but even highly skilled mountaineers would find it difficult to stop once a fall has happened. These are the conditions where roped climbing techniques are far more appropriate than the traditional skis over the shoulder kickstepping.

Later in the day, there is hope for softening snow on south-facing aspects such as Right Gully or Lobster Claw. Temperatures are forecasted to remain well below normal for this time of the year, so it may not happen at all. The best we can hope for is that the winds calm down quickly and the rain crust reacts quickly to the solar energy. Aspects that only receive morning sun, e.g. Hillman’s or Left Gully, are unlikely to soften unless temperatures go above what is forecasted.

FALLING ICE is a concern today. Recent warm temps and rain have weakened the bonds that hold the ice to the rock faces. Dark colored rock can warm and melt ice even on cold days, which can send it crashing down unexpectedly. You can help yourself by avoiding icefall zones, such as the middle floor of the ravine and near Lunch Rocks, or minimizing your exposure time if you do go there.

CREVASSES/OPEN HOLES have been growing. The Lip is a great area to avoid. The waterfall is open, there are crevasses growing on either side, there is a deep avalanche crown line, and the waterfall has punched another hole in the snow down low in the Lip, to the lookers left of the Open Book area. Hillman’s Highway has a spot that resembles a ice waterslide leading down into a dirty icy slot. You do not want to fall into this hole! Other areas to avoid include the Little Headwall and the stream leading out of the ravine. Also expect problems near any exposed rocks, where moats may have been created from the snowpack’s downhill creep.

The Sherburne Ski Trail is closed about a half mile uphill of Pinkham Notch. At the rope, you will need to cross over to the hiking trail and walk down to the parking lot. Do not walk the ski trail below the rope–it’s not built for foot travel and you will contribute to the erosion of this trail.

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 Mount Washington Volunteer Ski Patrol, or the AMC at Pinkham Notch Visitor Center or Hermit Lake Shelters.
  • Posted at 7:30 a.m., April 21, 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

2013-04-21 Printable