Avalanche Advisory for Wednesday, 4-25-2012

This advisory expires at midnight, Wednesday 4-25-2012

Tuckerman Ravine has Low avalanche danger. Natural and human triggered avalanches are unlikely. 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.

The summit is starting the day at 20 degrees F which will make for hard and icy snow surface conditions around the mountain.  A total of 3.7” of rain fell on the summit during the last weather maker from Saturday evening through Monday finishing off with a 0.7” dusting of snow yesterday.  The return of some seasonally cool air will keep snow showers in the forecast today giving the day a wintry feel, but it shouldn’t bring much accumulation. Moisture in different forms is expected to continue through the week before turning a bit better for the weekend.   Until then, fog is anticipated to continue on and off today which will have a bearing on your ability to recognize hazards in the Ravine. Clouds and foggy conditions may prevent you from seeing your runout, so a long sliding fall is to be avoided at all costs.  As we move into late spring skiing we often witness harder snow conditions whether it’s below freezing like this morning, or not.  Age hardening can slowly turn snow quite glacial, often labeled “alpine ice”.  This can be inconsistent across the terrain which highlights another reason to go up what you plan on descending, so you can witness the issues you’ll face.  Highly consider your run-out while climbing and skiing or riding.  Ask the question, “If I fall what is below me that I will be sliding into at a high rate of speed?”  Rocks, cliffs, crevasses, and bushes dominate the runout in most areas.  Assessing all the objective hazards together Left Gully harbors the least risk when comparing it to other locations around the Ravine.  That being said, less doesn’t mean none, so stay attentive and start conservatively.  Due to the very hard current conditions good mountaineering skills, crampons with front points and an ice ax to arrest a fall are essential and highly recommended for safe travel on steep snow.

CREVASSES AND UNDERMINED SNOW exists in many areas. These were made worse by the heavy rain earlier this week. Always climb up what you plan on descending so you can assess the hazards at a more leisurely pace. The largest crevasses exist from the Lip towards the south across the Center Headwall over to the Left Headwall, but smaller slots are growing in the Sluice and the Chute. Undermining or running water has increased the collapse hazards near holes, rock and crevasses as well. The lower sections of Hillman’s Highway have become discontinuous due the snowpack collapsing near the exposed rocks.

ICEFALL will continue to be a significant issueuntil it has all come down. Many people have been injured or killed through the years by falling ice and remember that even a small piece of ice impacting you at high speed can cause a lot of damage. Ice and rock has been falling from a variety of locations, including the less common areas such as Left Gully, the Chute, and Right Gully. But the dominate ice hazards are still from the Sluice moving south over to the Center Headwall. Due to harder snow conditions after the rain and cold air, ice can go much faster and farther than a week ago so realize you don’t need to go far to be at risk. Presently, if you’ve reached the snow line in the floor, you’re within striking distance of icefall!

THE TUCKERMAN RAVINE TRAIL IS CLOSED TO ALL USE FROM LUNCH ROCKS TO THE JUNCTION WITH THE ALPINE GARDEN TRAIL. This includes the Lip area as well as this section of the hiking trail. This annual closure is due to the magnitude of crevasses and undermining that develop in this area during the spring melt-out. A fall in this area would have severe consequences. The trail to the floor of the ravine is open from down below, as is the section above from the summit down to the Alpine Garden junction. Use an alternate route to circumvent this closed section, such as the commonly used Lion Head trail.  The John Sherburne Ski trail is also closed to all use.

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.  U.S. Forest Service, White Mountain National Forest

4-25-2012 Print Version