Avalanche Advisory for Friday 3-14-2014

Expires at midnight

Tuckerman Ravine has CONSIDERABLE avalanche danger.  Natural avalanches are possible and human triggered avalanches are likely.  Dangerous avalanche conditions exist. Conservative decision making is essential.

Huntington Ravines has MODERATE avalanche danger.  Natural avalanches are unlikely and human triggered avalanches are possible.  Evaluate snow and terrain carefully to identify features of concern.

AVALANCHE PROBLEMS: Wind Slab is the avalanche problem today.  Wind Slabs that developed through the recent storm and new wind slabs that are developing this morning are the immediate problem.  This afternoon, winds will increase and new snowfall will combine together to present another fresh round of wind slab loading over cold unstable slabs.  Fresh fracture lines are visible everywhere.  This is the #1 sign that instabilities exist and communicating to you that more potential exists.

WEATHER:  This storm gave us 18”(45cm) at Hermit Lake and is a good general average for the Mountain.  Today, cold NW winds will shift to the W and increase from 50 to 80mph.  Temperatures will warm from -15F to the + teens F late today as clouds intrude, drop, and bring some light snow.

SNOWPACK: Today is a great day to keep it simple and focus on the bulls-eye dataFracture lines or debris are visible in most avalanche paths, many being impressive.  Some fractures are deep and beat up signifying they happened earlier in the event.  In others, they are clean, thin, and crisp indicating they occurred much more recently.  Our terrain made a tremendous jump forward with this storm growing avalanche prone slopes substantially.  We’ll post pictures later.

In short, 18” of snow, winds gusting 80+ mph from the W and NW, and cold air in place has allowed unstable slabs to exist in many areas.  Some locations with deep fractures have obviously released their unstable slabs, although a number of them have seen some reloading.  Other locations are presenting smooth and engorged, holding their slabs like a gluttonous pig.  Today is a major heads up day and traveling safely will tax your safe avalanche experience and skills.  I believe a human triggered avalanche is likely on many Tuckerman’s slopes, hence the Considerable rating.  In Huntington, forecast areas are solidly in Moderate at the upper end of the rating definition, particularly from Central through South.  Some current active loading, light snow late in the day, and increasing wind keeps natural avalanches a potential in both Ravines.  In Tuckerman, they are more possible, but would keep it in your mind as a potential reality in Huntington as well.  Although I would consider naturals unlikely in Huntington they are not completely out of the question. Pay attention to natural loading and stay heads up to changing conditions.

With cold unstable slabs and the weekend on the horizon we are nervous.  We are changing beacon batteries, charging the Recco, changing out to big shovels, and tuning up the dog.  Seriously, it’s a heads up weekend!  Check out the Weekend Update this afternoon.     

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 900 a.m. 3-14-2014. A new advisory will be issued tomorrow.

Christopher Joosen, Snow Ranger
USDA Forest Service