Avalanche Advisory for Friday, 5-4-2012

This advisory expires at midnight, Friday 5-4-2012

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.   After the weekend we will be moving to a General Advisory for both Ravines which will be valid for up to 3 days per issuance.  Advisories will then discuss general hazards and conditions, but not daily specifics.  You will need to do your own snow stability assessments and daily weather investigation when this begins.

Well it looks like rain will dominate our existence on the mountain for another day.  A rumble or two of thunder is expected today with between 0.7” and 1.0” of rain delivered mostly through the morning and early afternoon.  A high pressure system will start to poke at the low pressure rain bully that has taken over the neighborhood beginning tonight.  Overnight rain will dissipate to showers with some clearing developing tomorrow offering only a slight chance of showers before the second half of the weekend brightens with the sun.  The high pressure should bring in cooler temperatures with the upper elevations dropping back into the 30’s F, adding a brisk feel to the May air.  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.   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.  Check out the Weekend Update this afternoon where we’ll get into some weekend weather details after another model run cycles through at noon today.

Rain all week has increased the deterioration rate increasing the rotting of any leftover hanging ice, snow bridges near crevasses, and the edges of holes. You won’t be able to see most of these in the fog before it’s too late, so your best bet is to altogether avoid the areas where you can find them.  Again, 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 increased icefall potential and crevasses. Hillman’s Highway is getting thinner with numerous breaks and rocks poking through.  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.

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

5-4-2012 Print Version