Avalanche Advisory for Monday, March 10, 2014

This advisory expires at 12:00 midnight.

Tuckerman Ravine has Moderate and Low avalanche danger.  Sluice, Lip, Center Bowl, and Chute have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. All other forecast areas have Low avalanche danger. Natural and human triggered avalanches are unlikely. Watch for unstable snow on isolated terrain features.

Huntington Ravine has Moderate and Low avalanche danger. Central Gully, Pinnacle, and Odell have Moderate danger. Natural avalanches are unlikely and human triggered avalanches are possible. All other forecast areas have Low avalanche danger. Natural and human triggered avalanches are unlikely, except in isolated terrain features.

AVALANCHE PROBLEMS: Difficult to trigger wind slabs will be the primary avalanche hazard early today with new storm and wind slabs developing later. Timing of new snow falling during snow shower activity will determine the degree of danger presented by these new slabs. If snow fall rates increase earlier than forecast, avalanche hazard will also increase. The persistent wind slabs in the Sluice through Chute areas remain a threat due to the potential size of a hard slab avalanche that could be triggered by a large load or on a thin spot in these locations. Continue to treat these areas with respect.  I would not want to descend steep avalanche paths in the late afternoon or evening as new slabs are likely to be touchy. There is the outside potential for these slabs to step down if the weakening ice crust is overloaded. An afternoon descent via winter Lions Head would be my choice over other options.

WEATHER: About a 1/2″ of snow fell in the early hours today with a trace to 2″ forecast through the day. 2-4″ more are forecast for tonight. West winds in the 25-40 mph range will diminish to 15-30 mph through the day while summits will remain obscured by clouds. Reduced visibility due to ground level clouds and light snowfall will be the rule today. Temperatures will be in the mid-teens F on the summit to mid-20’s at Pinkham Notch.

SNOWPACK: Existing surface conditions are predominately pencil hard wind slab with marginally softer slabs in some well protected lee areas such as Sluice through Chute in Tuckerman and other pockets throughout the ravines . Exposed ice crust exists as well, particularly in the fall line of gullies which have seen strong scouring action due to avalanche activity or wind erosion. Climbers left side of Left, Hillmans and South are examples of this. Expect new snow to form thin but touchy slabs today especially where it lands on the ice crust. It is hard to imagine that the small amount of snow will build to a depth capable of producing anything other than a small (D1) avalanche but even small avalanches can create problems when moving in steep terrain. Small natural sluff avalanches in a few very isolated areas would be within the realm of possibility but their small size doesn’t warrant a considerable or even moderate rating in our minds. Remember that a low rating doesn’t mean no avalanches.

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 Visitor Center, or the caretakers at Hermit Lake Shelters and Harvard Cabin.
  • Posted 8:15 a.m. 03-10-2014. A new advisory will be issued tomorrow.

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

2014-03-10 Print friendly