7:10 a.m., Thursday, November 28, 2002 This is a U.S. 5 Scale Danger Rating avalanche bulletin for Tuckerman and Huntington Ravines. We will likely go back and forth between General Advisories and 5 scale ratings until we need to go to a daily bulletin. If a 5 scale bulletin is issued it expires at midnight on the day of issue and you can expect another bulletin the following morning. When a General Advisory is posted another bulletin may or may not be issued the following day depending on conditions. Climbers heading into Huntington should check the avalanche bulletin before leaving Pinkham Notch or Hermit Lake each morning. Until the Harvard Cabin opens on December 1st the avalanche bulletin will not be posted there due to no campers being there overnight. Happy Thanksgiving!! TUCKERMAN AND HUNTINGTON RAVINES CURRENTLY HAVE MODERATE AVALANCHE DANGER. Natural avalanches are unlikely and human triggered avalanches are possible on steep snow covered open slopes and gullies. Be cautious in steep terrain. Light snow has been falling on the summit with a total of 2 inches for the 24 hours preceding the 12 midnight observations. Winds during the snowfall event shifted back and forth between WNW and the NW, where it is currently holding between 55-65 mph. The .19" water equivilant brought their snow density to a bit below 10%. Below the summit cone density was some what lower in the high single digits. The NW winds between 40-60 mph and light snow have made for ideal conditions for new loading on SE and E aspects and the cross loading of others. With even a couple inches of snow significant slabs can form when ideal densities and winds exist. In addition snow is being deposited on an ice crust that high winds swept clean in some locations during last weekends storm. Take this into account when determining stability with any new snow over the next several days. New snow falling on an ice crust won't bond nearly as well as those with snow deposits without a crust. This may cause over confident stability assessments if they are done in areas on new snow verses the ice crust. This spatial variability will be something to keep on the forefront of decision making over the next several days. I believe that if our snowfields were larger we may be at a Considerable avalanche danger level. So you may find pockets of instability on the high Moderate end approaching Considerable particularly in strong lee areas of NW winds. Light snow has continued since midnight and should taper into the morning hours, but blowing snow may persist which will continue bringing snow into the ravines even though it has stopped 'snowing'. Again this new loading into tomorrow may push some pockets to Considerable so keep an eye on the weather and its' effect on snow stability today and Friday. We are expecting light snow and snow showers over the next couple of days so watch for new bulletins discussing any change in the daily rating. Remember if the snowfield is large enough to ski, climb, or recreate on it's large enough to avalanche. AS ALWAYS, THIS ADVISORY IS ONE MORE TOOL TO HELP YOU MAKE YOUR OWN DECISIONS IN AVALANCHE TERRAIN. It should be used along with your own snow stability assessments, knowledge of safe travel techniques, skill in mountain weather's effect on the snowpack, and avalanche rescue. Pull out your beacon, probe, and shovel and practice, pracTICE!, PRACTICE!!, PRACTICE!!! ONLY YOU CAN SAVE YOUR PARTNER!! Sign up for an avalanche course. We have all the avalanche courses offered in the valley this winter on our website, csac.org. PLEASE REMEMBER: o Any new precipitation may increase the avalanche danger, this includes wind transported snow. o Obtain latest weather forecast before starting out. o For more information, contact the U.S. Forest Service Snow Rangers: AMC at Pinkham Notch Visitor Center or Hermit Lake Shelters. o This avalanche bulletin will expire at midnight. Christopher Joosen, Snow Ranger USDA Forest Service White Mountain National Forest