Avalanche Advisory for Friday, 4-20-2012

This Advisory expires at midnight, Friday 4-20-2012

Tuckerman Ravine has Low avalanche danger. Natural and human triggered avalanches are unlikely except in isolated terrain features. There is a possibility of isolated wet point releases/sluffing induced by human travelers and icefall triggers. 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.

Dramatic seasonal changes have once again shown their power this week through significant melting.  A week ago today Joe and I were post-holing in new cold snow up Hillman’s and above treeline on what felt like a nice January day.  Seven days later this same trip would feel like night and day.  Changes in the mountains aren’t necessarily bad, just different.  You can still have fun by altering your plans and expectations and understanding the hazards you may face.  This morning’s sunshine will give way to building clouds from day time heating producing a chance of afternoon showers.  Looking forward to the weekend, it doesn’t look too pretty, I’m afraid.  A chance of showers will grow to them being likely Saturday afternoon, producing about an inch of rain according to current information.  Sunday will also have wetness as the dominate weather factor.  There is a chance the higher summits may get some snow out of all this, but if I had to money down right now, unfortunately, I’d bet on rain.  Lower risk from objective mountain hazards (icefall, crevasses, avalanches) exist on the left or southern side of the Ravine than on the right, so staying to the Left Gully side of the Ravine is our recommendation.  Choosing our recommendation does not completely eliminate the hazards described below, but dramatically reduces your expose to them.  Check back to our Weekend Update this afternoon.

A lot of icefall has been occurring from the Headwall, Sluice, and other areas since last weekend. Many people have been injured or killed through the years by falling ice and a number of people had some very close calls earlier this week. Numerous large ice divots can be seen on the snow slopes below the Headwall and the Sluice.  The greatest hazard exists from these two areas, but there is some potential for this to happen in other locations.  Sitting at Lunch Rocks may be traditional, but it’s right in the cross-hairs of some significant ice shelling from multiple directions. In general, you should always be thinking about what might fall from above…ice, rock, avalanches, dropped snowboards and skis, etc.  So stay aware! 

The Center Bowl and Lip areas have numerous deep crevasses, undermined snow, and waterfall holes. Because the consequences of falling into one of these crevasses are severe we recommend avoiding this area entirely. Hikers should not use the Tuckerman Ravine Trail to travel through the Ravine to the alpine zone and the summit of Mt. Washington. Descending into the Ravine from above is also not recommended.  Remember, just because a bootpack exists in the snow it doesn’t mean it was a safe choice by the past users.  From Pinkham, Lion Head is a much better option. The Tuckerman Ravine Trail from the rim of the Ravine to Lunch Rocks will be closing very soon because of these developing hazards.  This annual closure occurs due to the magnitude of crevasses and undermining that develop during the spring melt-out.  There are smaller crevasses outside of the Lip and Center Bowl area.  As an example underneath the Sluice ice is an area where we’ve historically seen dangerous undermined snow and crevasse hazards. Hillman’s Highway is yet another area where undermined snow can be found.

The John Sherburne Ski trail is now closed to all use due to rapid melt out this week.  Avoid mud over your boot tops and eroding the trail by walking down to Pinkham Notch from Hermit Lake on the Tuckerman Ravine hiking 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 AMC at the Pinkham Notch Visitor Center, or the caretaker at Hermit Lake Shelters.  A new advisory will be issued tomorrow.

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

2012-04-20 Print Version