Avalanche Advisory for Thursday, 4-19-2012

This advisory expires at midnight, Thursday 4-19-2012

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.

Another warm day is in store for the region today as the latest Midwest weather system move in our direction.  This will drive summit temperatures warmer than yesterday sending the mercury to about 40 degrees F.  Mild air associated with low wind speeds and periods of sun, will once again heat up the Ravine.  South aspects and ice pointing directly into the sun will be most affected and weakened.  As we move into Friday clouds will be on the increase as warm precipitation moves into the area.  Currently temperatures on the summit are forecasted to hit the mid-forties with rain a possibility late tomorrow.  As we head into Saturday precipitation potential will increase from close to 60% in the morning to 80% late with water amounts between 0.3-0.5” (0.8-1.25cm).  In the northern portions of the State the water accumulations are close to double so we’ll be watching the developing track closely. This entire scenario will continue icefall concerns over the next 72 hours.  A fair amount has fallen since last weekend, but more is looming as we try to get through the last half of existing ice in the Ravine.  As I said yesterday there is still enjoyment to be had with skis and boards, however realize timing and hazard recognition is everything.  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.

Icefall has been occurring from the Headwall, Sluice, and other areas. Many people have been injured or killed through the years by falling ice and a number of people had some very close calls this week.  The greatest icefall hazard exists from the Center Headwall and the Sluice ice above Lunch Rocks, 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 significant ice shelling from multiple directions.  Most of our icefall tragedies have happened at Lunch Rocks (Icefall Rocks) so they should be avoided as your base camp.   In general, you should always be thinking about what might fall from above…ice, rock, avalanches, dropped snowboards and skis.  And although you may not of considered falling people a hazard we have seen many people down lower be taken on by those falling from above on steep slopes. 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. 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 hazard. Hillman’s Highway is yet another area where undermined snow can be found.

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.  From Pinkham, Lion Head is a much better option. 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, the caretaker at Hermit Lake Shelters. A new advisory will be issued tomorrow.

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

4-19-2012 Print Version