Avalanche Advisory for Sunday, 4-08-2012

This advisory expires at midnight, Sunday 4-08-2012

Tuckerman Ravine has Low avalanche danger. Natural and human triggered avalanches are unlikely except in isolated terrain features. These pockets do exist.  Huntington Ravine is under a General Advisory. You will need to do your own snow stability assessments when using avalanche terrain in Huntington. A danger of falling ice exists, and will persist until it all comes down.

Weather and its effect on Mount Washington continue to impress me.  Only 3 weeks ago we were enduring an unprecedented heat wave melting the Ravine before our eyes.  We knew this could all change again, but the season’s longevity wasn’t looking pretty.  As the heat was ushered out winter returned and really hasn’t left!  Tuckerman’s coverage has been close to a state of suspended animation, changing ever so slowly.  Big ice has redeveloped in the Sluice and Headwall joining older ice from the winter, crevasses are slowly growing and undermining is present although fairly stagnant.  Then, just to be difficult, Mother Nature has hidden these by steady shots of new snow causing some avalanche concerns.  Overnight the summit received 2.5” (6cm) of light 3.6% density snow on N/NW winds from 35 to 55mph (56-88kph).  This adds up to 10.5” over the past week which has been filling in the nooks and crannies and giving us some snow stability concerns.  Old surface is still present in most of the Ravine, however isolated low density pockets of slab could be triggered by a human traveler particularly locations high and tight under terrain features on the steepest slopes between the Headwall and the Sluice.  An additional inch today and possibly another 4” tomorrow with W winds gusting over 70mph will increase the avalanche danger.  Until then today’s bulls-eye points in addition to avalanche concerns are:

  1. FOG WILL LIMIT YOUR HAZARD ASSESSMENT.  Fog forecasted today will make assessing all the hazards you face very difficult, this dramatically increases your risk.  Many seasoned mountaineers consider fog a “no-go/red light” day.
  2. The northern side of the Ravine, primarily the Lip area, has the vast majority of large crevasses.  These have been obscured by recent snowfalls, making them impossible to safely assess, but it’s entirely possible that you would fall into one if you were to ski, hike, or slide over it.  Many of these are very deep with severe consequences. Travel from the Ravine floor to the ridgeline on the climber’s right side of the Ravine from the Center Bowl to the Sluice, including the “Lip” area IS NOT RECOMMENDED AND SHOULD BE AVOIDED.  
  3. Hikers should not use Tuckerman Ravine to access the Alpine Zone and the Summit of Mount Washington.  Equally, they should not descend down from these areas into the Ravine.  The Lion Head trail is a much safer option.  Of course be prepared with appropriate clothing, an ice ax, and crampons.  
  4. The southern side of the Ravine, including the Chute and Left Gully has far less “objective hazards”, such as icefall, undermining, crevasses, and avalanches than on the northern side. These are dangers you can’t control, but you can avoid them by choosing where you travel. Your overall risk is far lower in these southern locales, or left side of the Ravine.  As in all locations think about long sliding falls due to hard surface conditions.

Whether you’re on skis or on foot, falling in steep terrain is not an option. An ice axe, crampons, and real mountaineering boots are absolutely critical for climbing safely in these conditions. Simply having these tools isn’t enough. You need to know how to use them, and understand the limits of their effectiveness in steep icy terrain. The hard old surface makes belayed climbing on the steeper slopes a wise technique. Also think about what is below you—rocks, chunks of ice, crevasses, etc—these greatly increase the consequences of a sliding fall.

Again, crevasses, undermined snow, and waterfall holes are a serious threat. Currently the area from the Sluice to the Center Bowl is littered with crevasses. New snow makes them nearly impossible to see. The hazards presented by the crevasses are not to be taken lightly; consider it “no-fall” terrain.  Because of the extent of crevasses, the severity of the consequences, and the inability to assess the hazard, the greater Lip area, which includes a section of the summer hiking trail, should be avoided entirely.

Falling ice can also happen, even on cold days. A couple times over the past week we have watched ice fall into Lunch Rocks while air temperatures were below freezing. Your best defense against falling ice is to avoid being anywhere near the possible runouts. The locations at greatest risk for this hazard are the Sluice, Lunch Rocks, the Lip, and the Center Bowl. Other areas aren’t immune though, so always be aware of what’s above you. And remember, ice doesn’t always fall in a straight path downslope.

The Sherburne Ski Trail is still open about 1/3 of the way down and is currently a mix of lots of water ice, exposed rocks, with a little bit of new snow hiding these problems.  Cross over to the hiking trail at the rope.

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, and the AMC at Pinkham Notch or Hermit Lake.  A new advisory will be issued tomorrow.

Christopher Joosen, Snow Ranger
USDA Forest Service, White Mountain National Forest

2012-04-08 Print Version