Avalanche Advisory for Friday, 3-30-2012

This advisory expires at midnight, Friday 3-30-2012

Tuckerman Ravine has MODERATE avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible.  Heightened avalanche conditions exist on specific terrain features.  Evaluate snow and terrain carefully to identify features of concern.  The Lobster Claw, Right Gully, the Lower Snowfields, and the Little Headwall are not posted due to lack of snow.

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.

As of this morning the summit received another 3.5” (8.9cm) over the past day, giving us close to a foot (30cm) since the weekend.  Although we do have new snow in the Ravine, don’t expect a blanketed foot of snow laid evenly across the mountain.  Generally we’re wondering where it all went.  A great deal of blowing snow likely got eaten up by the irregular terrain above treeline due to the early spring melt-off that occurred.  Like in the early season, the nooks and crannies can make a lot of snow disappear before it makes it to the Ravine’s edge.  However, I was pleasantly surprised to be hiking through a few inches of snow on the trail just below Hermit Lake.  The Ravine is still cloaked in secrecy by clouds, fog and blowing snow so we have yet to see the outcome of new snow loading from the past 48 hours.  Nevertheless we’ll get into the terrain this morning to find out what we can.  Once again high winds, peaking at 78mph (126kph), undoubtedly blew new snow off icy cold slopes exposed to NW winds such as down low in the Bowl, particularly on the southern end below the Chute.  Conversely, I would expect new slabs that developed in sheltered locations, strong lee areas and in upper start zones near the horizon, to have stability concerns.  Summit temperatures over the past 72 hours ranged from the twenties down to a current of +1F, so snow has remained fairly cold being slow to stabilize.  In addition, upwards of another couple inches are expected today on NW winds currently gusting 60-70mph, and dropping to 35-50+ later.  This will continue to load snow available from the alpine zone into the Ravine.  Until some clearing conditions develop later I would be conservative due to visual clues being a bull’s-eye piece of data today.  The old grey snow and the fresh white snow will be in excellent contrast to one another allowing you to discern very stable old surfaces to questionable new snowfields.  We will post any updated information in the Weekend Update later today so come on back to www.mountwashingtonavalanchecenter.org

Due to frozen surface conditions long sliding falls are a significant threat to all mountain travelers in angled terrain. The slick icy surface will allow for rapid acceleration down slope potentially sending you into numerous obstacles below you.  Exposed rocks, chunks of ice, trees, and moguls that feel like rocks all make the sliding fall potential much more hazardous. An ice axe, full 10-12 point crampons, and real mountaineering boots are absolutely critical for climbing in these conditions safely.  Because the current surface conditions have made most steep slopes “no fall” territory the experience and skills to use this equipment is imperative.  If you have to rent this equipment I would think twice.

Undermined snow and crevasses have emerged in recent weeks. Overall, the worst of the crevasses can be found in the Sluice, through the Lip and into the Center Headwall. Undermined snow can be found in many locations, including Hillman’s and Left Gully. Cold temperatures this week have strengthened snow in relation to these issues, but you’ll still want to know where they are so you can avoid them. Realize falling into an open crevasse from above is potentially more likely due to the icy surface conditions and fog than when it’s soft and clear.  We recommend climbing up what you plan to descend so you can learn about these hazards.

Falling ice should remain in the back of your mind as well. Below-freezing temperatures generally pose less risk than very warm days, but the freeze-thaw cycles can work to dislodge rock and ice from steep terrain, sending it down onto anyone or anything in the runout.

The Harvard Cabin at the base of Huntington Ravine will close on Sunday for the season.    The Sherburne Ski Trail, full of icy bumps coated in a few new inches of snow, is open about 1/3 of the way down.  Cross over to the hiking trail at the closure rope.  New snow is helping cover the frozen water ice on the Tucks trail below Hermit Lake, but traction devices on your feet will be very helpful 

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, the AMC at the Pinkham Notch Visitor Center, or the caretakers at Hermit Lake Shelters or the Harvard Cabin.  A new advisory will be issued tomorrow.

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

2012-03-30 Print Version