Avalanche Advisory for Tuckerman and Huntington Ravines


 Posted: 8:33 a.m., Thursday, December 13, 2007


 Tuckerman Ravine has MODERATE and LOW avalanche danger today.


 Hillman's Highway, The Bowl, Headwall, and the Lip have Moderate
 avalanche danger. Natural avalanches are unlikely and human triggered
 avalanches are possible. Unstable slabs are possible. Be cautious in
 steeper terrain. Left Gully, Right Gully, and the Little Headwall have
 Low avalanche danger. Natural avalanches are very unlikely and human
 triggered avalanches are unlikely except in isolated pockets. Normal
 caution is advised. The Lower Snowfields will remain "Not Posted"
 until it fills in with more snow. Forecasts for this location will
 begin when needed.


 Huntington Ravine has LOW avalanche danger. Natural avalanches are
 very unlikely and human triggered avalanches are unlikely except in
 isolated pockets. Normal caution is advised.


 Extreme winds create extreme results! Tuckerman has seen quite a
 change in the past 24-48 hours. As Jeff said this morning "the Ravine
 went through a quick coming of age as it to bed a boy and woke up a
 man". Snowfields and gullies filled in dramatically in multiple
 locations as about 8" (20cm) of snow over 2 days finished with winds
 gusting to 117 mph (190kph) from the WNW yesterday afternoon. Evidence
 of avalanche activity can be seen in Dodge's Drop, the lower left side
 of the Bowl, and perhaps Left Gully. Since this cycle occurred,
 probably around late morning on Wednesday, we have received heavy
 scouring and wind packing in most areas in both Ravines. This has
 generated increased stability in all areas compared to yesterday. The
 greatest concern however is the typical Tuckerman locations that are
 in the strong lee of NW to W winds, namely The Lip and high under the
 main headwall ice particularly on the northern side (climber's right)
 approaching the Lip. This is the reasoning for the Moderate posting in
 these areas. Saying this you will find increased stability down low
 under the Chute and the Southern side of the Bowl. Keep in mind that
 you will be in the run out of instabilities above these locations. We
 are now being set up for more avalanche activity in the future as our
 bed surfaces have grown considerably. This will be something to think
 about right away as we will pick up some snow overnight and again
 Friday although accumulations will remain light. Saturday night and
 Sunday are much different as it currently appears we will get a
 pummeling as a major winter storm bears down on northern New England.


 This will be a big discussion point in the advisory over the next 2
 days as well as the "Weekend Update" Friday evening. So stay tuned!!


 By now you've probably waxed your skis, sharpened your ice axes,
 refreshed your knowledge of stability assessment, and practiced your
 rescue skills. No matter how experienced we all are these skills fade
 with time. Now is the time to hone those skills. Your lives depend on
 it! We have all the avalanche courses offered in the valley this
 winter on our website, www.avalanche-center.org.


 The John Sherburne Ski Trail is open, with continuous snow from top to
 bottom. Many large waterbars and exposed rocks make this a challenging
 early season ski. The Lion Head Summer Trail is currently open. The
 change to the Winter Route will occur when snow conditions warrant.


 We'll let you know of the change when it takes place.


 Please Remember:
 o It is impossible to accurately predict natural events, such as
 avalanches, in every instance. This Advisory is one tool to help you
 make your own decisions in avalanche terrain. It should be used along
 with safe travel techniques, snow stability assessments, an
 understanding of weather's effect on the snowpack, and proficiency in
 avalanche rescue.


 o You should obtain the latest weather forecast before heading into
 the mountains. Anticipate a changing avalanche danger when actual
 weather differs from the National Weather Service forecast.


 o For more information, contact the U.S. Forest Service Snow
 Rangers or the AMC at Pinkham Notch Visitor Center or Hermit Lake
 Shelters or the HMC caretaker at the Harvard Cabin. This advisory will
 expire at midnight.


 Christopher Joosen, Snow Ranger
 USDA Forest Service
 White Mountain National Forest