Avalanche Advisory for Sunday May 10th, 2015

This advisory expires tonight at 12:00 midnight.

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 traveling in avalanche terrain in Huntington. A danger of falling ice exists, and will persist until it all comes down.

AVALANCHE PROBLEM: Continue to manage your sluff, especially if you are above terrain hazards like cliffs and crevasses or on seldom skied lines. The four threats of the big five (Avalanches, Weather, Ice Fall, Crevasses, and Undermining) discussed below should be a greater focus over avalanche potential today.

WEATHER:  The potential for showers and thunderstorms will grow through the day and are likely this afternoon. Some weather models are hinting that a few thunderstorms maybe severe so be prepared for periods of heavy rain, small hail, and strong gusty winds in alpine zones. Thunder equals lightning so avoid being high on the mountain or ridges when this comes in today.  Getting down to lower elevations and staying far away from higher terrain features will be important.  High buttresses, Lion’s Head, Boott Spur, and The Three Stooges near Dodge’s Drop are several examples of places to avoid based on being good lightning targets.

FALLING ICE: Falling ice remains a substantial and imminent hazard.  This is proven by some very large ice fall already this morning.  We are right in the middle of peak ice fall season! Massive blocks still cling to the Center Headwall cliffs as well as in the Sluice, directly above Lunch Rocks. Avoiding this area, otherwise known as “Icefall Rocks”, will dramatically reduce your overall Icefall risk.  Reducing time spent in areas below ice while on skis also limits your exposure to this threat. Don’t underestimate the speed and random trajectory of chunks of falling ice. Many people have been seriously injured or killed from falling ice in Tuckerman Ravine. There are no specific warning signs outside of general warm weather and melting.

UNDERMINED SNOW: This hazard develops where the snowpack has a stream or river of meltwater running beneath. In general, areas where you might expect the largest volume of flowing water will create the most undermining with a thinning snow bridge above. The main waterfall hole to the climber’s left of the Lip has grown considerably with the increasing flow due to melting. If you go into this waterfall hole it is likely that you will not come out and has been the cause of past fatalities. Give a wide berth to this and other holes in the snowpack!

CREVASSES: The number of crevasses is greatest in the Lip and Sluice, but other locations have these slots opening up as well. These can be covered by hidden breakable snow bridges. Many of these are wide enough to fall into and they are probably much deeper than you think. The largest concentration of these slots in Lip and Sluice is best avoided, especially when traveling on foot.

THE BOTTOM LINE: Areas offering the largest snow filled gullies with the least amount of risk from icefall and crevasses are found either on the climbers hard right or left edges of the Ravine.  On the right side, Right gully or the thinner Lobster Claw offer reasonable options, but expect some undermining. Among the left side options, Hillman’s Highway and Left Gully are the longest runs and avoid the higher level of risk and potential grim outcomes found in the Sluice, Lip, Center Bowl and Chute.  But again, expect some undermining.  The Little Headwall has melted out and is a raging waterfall.  Your only option is to walk down the trail to Hermit Lake from the floor of the Ravine. From there, the Sherburne Ski Trail is open for about 2/3’s of a mile for the last day.  You’ll have to click out about 5 times this morning, maybe more this afternoon, to make it to the rope. From there, walk the Tuckerman Ravine Trail back down to Pinkham. Call your Mother today or you’ll be in trouble.  Happy Mother’s Day, thanks for all you do!

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, or the AMC at the Pinkham Notch Visitor Center and Hermit Lake.
  • Posted 7:55 a.m., Sunday, May 10, 2015. A new advisory will be issued tomorrow.

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