Avalanche Advisory for Tuesday, February 19, 2013

This advisory expires at 12:00 midnight, February 19, 2013

Tuckerman Ravine has Moderate and Low avalanche danger.  Right Gully, the Lip, and Center Bowl have Moderate avalanche hazard.  Natural avalanches are unlikely and human triggered avalanches are possible. Lobster Claw, Chute, Left Gully, Hillman’s Highway, the Little Headwall, and Lower Snowfields have Low avalanche hazard.  Natural and human triggered avalanches are unlikely.

All forecast areas of Huntington Ravine have Low avalanche danger.  Natural and human triggered avalanche are unlikely.

The damage done to our snowpack by yesterday’s high winds (129 mph or 210 kph peak wind speed) is the overwhelming impression of Tuckerman from Hermit Lake. Field time yesterday afternoon revealed evidence of four avalanches though the evidence of more would have been erased by the high winds.  Firm, stable, wind sculpted snow is the predominate surface in most of Huntington and Tuckerman Ravines today. Larger areas of windslab exist in the gullies rated Moderate with smaller pockets in Low rated gullies. The windslab creating our concern today will appear smoother and will be less resistant to triggers than the more textured and sculpted areas.  Beware of cracking and hollow sounding slabs in select lee areas. Though further field time today will help us more accurately pin down the hazard in our Moderate rated gullies within that rating, some clues visible from Hermit Lake point to the fact that further loading occurred as the winds died down overnight.  The three foot crown line below the ice in the Lip area has reloaded so that only about a foot, or maybe a bit more, is now visible. Right Gully was loaded more than scoured during the event but with little snow prior to the wind, only enough new slab exists to create a Moderate hazard.  Center Bowl and the Chute were heavily wind packed but some hangfire still exists in the upper portion of the hourglass below the ice in Chute.  The climbers upper left exit of Left Gully slid and didn’t reload but the upper right pocket would be best avoided or approached carefully. Hillman’s Highway was scoured out or wind hammered.  Huntington Ravine gullies suffered significant scouring.  The northern gullies look like they did a month ago…rocks near the top and a thin ribbon of ice and snow below. Central, Pinnacle and Odell Gully were also mostly scoured.

Today’s weather forecast is creating a good window for those looking to get out and climb and hike during this busy vacation week. Forecasting for crowds has proven to be challenging but it is safe to say that more than the usual caution is warranted due to the increased likelihood of people generating rock and ice fall or even finding the sweet spot that triggers the slab above you. Afternoon fog and cloud cover is forecasted to descend through the afternoon as winds increase so consider your pace and account for deteriorating visibility. Temperatures will rise to the mid 20’s on the summit but we have already hit 32F (0C) at Hermit Lake at 7:30 am with calm winds. Enjoy the balmy conditions while they last.  Enough snow is forecasted tonight and tomorrow to change our avalanche animal dramatically so check in tomorrow morning for the latest forecast before committing to a route.

Remember that Lions Head trail is a steep mountaineering route with several areas of 3rd class rated terrain.  Climbing rock and steep snow and ice slopes in crampons may require ropes to protect you or members of your party.  Anticipate possible delays due to crowds and be patient with others as they negotiate this terrain which has been the scene of numerous injuries in the past.

 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 caretakers at Hermit Lake Shelters or the Harvard Cabin.
  • Posted 8:15a.m., February 19, 2013. A new advisory will be issued tomorrow.

Frank Carus, Snow Ranger
USDA Forest Service
White Mountain National Forests
(603) 466-2713 TTY (603) 466-2856

2013-02-19 Print friendly