Avalanche Advisory for Thursday, March 13, 2014

This advisory expires  at midnight.

Tuckerman and Huntington Ravines have HIGH avalanche danger.  Natural avalanches are likely and human triggered avalanches are very likely. Large avalanches are expected on a variety of slope aspects and angles. Very dangerous avalanche conditions exist and travel in avalanche terrain is not recommended.

AVALANCHE PROBLEMS: Storm Slabs from the 14” snowfall will be the primary avalanche problem this morning. The size and destructive power of avalanches today will increase rapidly as Wind Slabs build due to increasing Northwest winds. Travelling in avalanche runouts, like the floors of both ravines, is not recommended due to the risk of natural avalanche activity. The rescue cache (Connection Cache) just as you enter Tuckerman could be overrun by avalanche debris. Avalanches will be large and may even step down into older persistent weak layers and grow even larger.

 WEATHER: As of midnight this storm system has delivered 14” of 10% average density snow to the summit of Washington. This was delivered on a general S and SE wind, peaking in the 40’s mph. Since midnight light snow has continued and should give us another 2-4” today.  Currently, very low velocities have begun the clockwise shift towards the NW where they are forecasted to sit today and start screaming.  Through the day, winds will build and are anticipated to gust over 80 mph late in the day.  Expect zero visibility as a large volume of alpine snow becomes airborne and transports to SE and E facing slopes.

 SNOWPACK: Yesterday’s snow and new snow today on these forecast winds makes a snowpack discussion pretty much irrelevant when it comes to making travel decisions today.  The storm started out fairly cold with some wind and then turned warmer and wetter without much wind and then turned cold again. This means we have a relatively light layer of wind affected snow with denser snow above. Add to this a load of wind slab as West then Northwest wind ramps up with additional new snow today and widespread avalanches are the result. To sum up, today is a good day to find cold snow somewhere on lower angled terrain in the woods with a careful eye of where avalanches from above could run.

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 7:00am 3-13-2014. 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

2014-03-13 Print Friendly