7:08 a.m., Tuesday, December 3, 2002 TUCKERMAN RAVINE CURRENTLY HAS BOTH MODERATE AND HIGH AVALANCHE DANGER. The Little Headwall and the Lower Snowfields have MODERATE avalanche danger. Natural avalanches are unlikley and human triggered avalanches are possible on steep snow covered open slopes and gullies. Use caution in steeper terrain. All other areas in Tuckerman Ravine have HIGH avalanche danger. Natural and human triggered avalanches are LIKELY on a variety of aspects and slope angles. Travel in avalanche terrain, which includes runout zones, is not recommended. HUNTINGTON RAVINE HAS HIGH AVALANCHE DANGER. Natural and human triggered avalanches are LIKELY on a variety of aspects and slope angles. Travel in avalanche terrain, which includes runout zones, is not recommended. The summit has received 4.7 inches of 3.6% density snow in the past 24 hours. This is close to the lightest appreciable snow I have seen here on Mt. Washington. It came in with light winds through the day which has steady increased since about 3 am when temperatures began dropping. Winds made a shift from the WNW to the NW as this occured and are currently gusting into the 80+ mph range. The high winds associated with 3.6% snow should load both Ravines with new slab through the day. In addition to blowing snow, snow showers are expected through the morning hours. The light winds of yesterday afternoon and early last night began loading lee areas in both ravines with a light soft slab. As winds increased and are forecasted to continue today I expect to see a denser slab form on top of some loose unconsolated snow and soft slabs. High winds should have no problem both eroding existing drifts above treeline as well as battering new crystals into smaller snow particles once aloft. Since the winds have picked up I don't believe crystals have been able to keep their orginal form. These smaller particles with high winds should pack into a higher density slab than layers underneath. This should once again form an unstable inverted snowpack with heavier slabs over lighter density unconsoladated snow and soft slab. Expect this wind and light snow combination to bring more snow from lower elevations on the windward side of the mountain than usual. Expect the heaviest loading to occur on E, SE, and S facing aspects, but be prepared for slabs to form on a variety of slopes aspects and angles. 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. THE LION HEAD SUMMER TRAIL TRAVERSES NEAR TREELINE SHOULD BE WATCHED CLOSELY FOR AVALANCHE POTENTIAL. Each year the Lion head winter route is opened once the summer trail snowfields become large enough to become a consistant avalanche threat. We will be changing the trail over this week due to new loading increasing the size of the traverse snowfields. YOU MAY FIND AVALANCHE CONDITIONS IN THIS AREA SIMILAR TO THE RAVINES DUE TO THE LIGHT SNOW AND HIGH WINDS. You need to be knowledgeble in stability assessment in addition to safe travel techniques to travel safely in this area. Have the avalanche gear, travel one at a time, don't travel over under or over one another, and have a plan in mind about what you will do if an avalanche occurs. Watch for the change of trail signs. The winter route leaves from the Huntington Fire road and has orange signs. The summer route has white signs and leaves the Tuckerman Ravine trail near Hermit Lake. As mentioned over the past several days I will try to point out some mistakes made during the 2 avalanche accidents over the next week. The intent is that we can all learn from these events to prevent future accidents and be better prepared as backcountry users in avalanche terrain. Some items that jump out at me are, potential misunderstanding of the 5 scale avalanche danger rating system, lack of avalanche safty equipment, lack of avalanche training, and breaking the rules of safe travel in avalanche terrain. The 5 scale system is used through out the United States and Canada. Each level, in ascending order of danger, LOW (green), MODERATE (yellow), CONSIDERABLE (orange), HIGH (red), and EXTREME (red with black border) have a SPECIFIC definition tied to them. We use the exact definition when describing each level of danger. The 5 words 'unlikely', 'possible', 'probable', 'likley', and 'certain' are very important to understanding each danger level. Focus on the definition wording not the discriptor. Such as in the level Moderate or Considerable. These 2 words may mean different things to different people so use it to link to the definition words, "possible" and "probable". Also realize that each danger level is not a specific point of instability. It covers a range of instability before either moving down or up to another level. At times when it's just a bit above 'Low', the appropriate danger level is 'Moderate'. Other times when it's just about at 'Considerable', but not quite, the appropriate level is again 'Moderate'. So, for two different situations and stabilities it may be, appropriately, the same rating. In short try to remember 2 important things. The definitions are much more important than each discriptor word, Low through Extreme, so memorize them. And second, each level covers a range of instability not a point on the stability spectrum. 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