This advisory expires at midnight, Thursday 5-03-2012
Tuckerman Ravine has Low avalanche danger. Natural and human triggered avalanches are unlikely except in isolated terrain features.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.
Precipitation potential will increase this afternoon as the next weather maker moves into our region turning fog, drizzle, and some showers into a more consistent rain event. Depending how you blend the weather model predications, somewhere around an inch (2.5cm) of rain should fall over the next 36 hours. I’m a little reluctant to say much definitive about Saturday’s precipitation right now because the speed and track of this system has vacillated a bit over the past day. However, weather on Saturday will improve from the 80-90% chance of rain later today and tomorrow. All indications point to continued moisture in some form over the next 72 hours before some better weather on Sunday as a high pressure slips in briefly for a pleasant Monday. In addition to the typical spring hazards discussed below being exacerbated by rain, anticipate fog to hinder your ability to recognize them. Be very conservative if visibility is limited. I would consider avoiding the Ravine as seeing crevasses, and particularly falling ice, is nearly impossible if the fog is thick and the light is flat. Fog should be a more consistent problem tomorrow, but be ready for changing conditions today as the cloud deck may move up and down. Take any clearing weather opportunities to give the Ravine’s terrain some focused attention. Quickly try to determine where ice is hanging, where open holes loom, and where crevasses are located before fog rolls back in. We’ll try to give some better weekend weather news to you in tomorrow’s advisory and weekend update Friday afternoon. Until then be ready for rain with good mountain shells and dry clothing to swap out. 40 degrees F and rain can be worse than a dry cold midwinter day to cause hypothermia.
Expect the continuation of our typical springtime hazards such as icefall, crevasses and undermined snow as liquid precipitation accelerates melting. You won’t be able to see any of these before it’s too late, so your best bet is to altogether avoid the areas where you can find them. Warmth and rain will create ideal conditions for falling ice! For the most continuous snow coverage and the fewest objective hazards, head to Left Gully. From the Chute across to the Sluice you’ll be dealing with a lot of icefall potential and crevasses. Hillman’s Highway also has reasonable snow coverage, but the lowest portion has become discontinuous due to melt out and undermining.
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 from Pinkham Notch to the floor of the ravine is open, as is the section above the Ravine from the Alpine Garden Trail junction to the summit. 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.
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