Posted 8:10a.m., Thursday, January 06, 2011
Tuckerman Ravine has Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. The Lower Snowfields and Little Headwall remain not posted due to a lack of snow in these areas.
Huntington Ravine has Low avalanche danger. Natural and human triggered avalanches are unlikely. Watch for unstable snow on isolated terrain features. The Escape Hatch remains not posted due to a lack of snow in this area.
Today is a great opportunity to practice being your own weather observer. Two key factors to watch for are 1) how much snow is falling and 2) how are the wind directions and speeds affecting the new snow. I know that may seem like a no-brainer to anyone who has even the slightest clue about snow stability, but today’s weather forecast is dynamic and variable. These two factors will play a prominent role today in just how far up the avalanche danger scale we go. Tuckerman Ravine starts the day with Moderate avalanche danger. This is due to the 3.5″ (9cm) of new light density snow that has fallen over the past few days, coupled with strong W and NW winds. Expect new windslabs to already exist in most areas of Tuckerman, sitting on top of a frozen hardpack left over from last week’s rain. Today’s wild card is the potential for upslope snow showers. The Observatory is forecasting a trace to 2″ of snow today, and the difference between the two ends of the range can make a big difference. If we meet or exceed the 2″ forecast, you should expect avalanche danger to be pushing the upper boundaries of the Moderate rating, which means you ought to be thinking about the possibility of natural avalanche activity. On the other hand, if we only get a trace, we’ll still have danger ratings sitting squarely in the Moderate range. Winds are forecasted to come down in speed and then shift directions late in the day. Loading may subside some as speeds decrease, but pick back up again as new snow falls or the directions shifts to the SW. Pay attention to what’s going on today and be flexible with your plan.
Yesterday’s strong winds have scoured much of the light density snow out of the gullies of Huntington. This is the primary reason why Huntington is rated at Low avalanche danger, even though the mountain has received over 3.5″ (9cm) of new snow. In isolated terrain features you should be watching for isolated pockets of unstable snow. The chances for this are greatest in the upper parts of the fan and down low in the gullies. As with Tuckerman, you’ll need to pay attention to how much snow falls today. If we meet or exceed the forecasted amounts expect increasing avalanche danger.
Anyone venturing onto the mountain needs to be ready with good traction from the base of the mountain to the Summit. Long sliding falls are a real potential in steep terrain and in places on the Tuckerman Ravine trail below Hermit Lake. Crampons or similar gear are a must right now and solid self arrest skills are critical for anyone venturing into the steeps. Despite a few inches of new snow, the Sherburne Ski Trail is in bad shape. Even the most optimistic skier or snowboarder would have a difficult time calling it good.
- 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.
- This advisory expires at midnight. A new advisory will be issued tomorrow.
Jeff Lane, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856