Avalanche Advisory for Tuckerman and Huntington Ravines
Posted: 7:53 a.m., Friday, December 7, 2007

Tuckerman Ravine has CONSIDERABLE, MODERATE and LOW avalanche danger today. The Lip, Bowl, and Headwall have Considerable avalanche danger. Natural avalanches are possible and human triggered avalanches are probable. Be increasingly cautious in steeper terrain. Left Gully has Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. Use caution in steeper terrain. Hillman's Highway and Right Gully 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 and the Little Headwall have little to no snow in them so they will remain "Not Posted". Forecasts for these locations will begin when needed.

Huntington Ravine has MODERATE and LOW avalanche danger today. South, Odell, Pinnacle, Central, and Yale have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. Use caution in steeper terrain. The Escape Hatch, Damnation, and North gullies have Low avalanche danger. Natural avalanches are very unlikely and human triggered avalanches are unlikely except in isolated pockets. Normal caution is advised.

Winds were expected to decrease yesterday afternoon but contrary to all forecasted wind velocities the summit gusted from the west to 91mph (145kph) late in the day. From 9am to 7pm winds gusted above 70mph (113kph) pushing towards 80mph (129kph) for several hours. It was a great example of how sometimes natures decides what it wants to do even when we think we can predict her every move. These high winds moved snow into the Ravines through the day pushing the avalanche danger ratings to their full definitions. This new loading and today's forecasted snow showers in the afternoon are the rationale for a bump in some ratings. Lee areas of WNW winds in Tuckerman loaded with the most new snow, hence the move to "Considerable" for these areas. In Huntington the focused areas of concern are Odell, Pinnacle, and Central gullies. Expect these gullies to have variable conditions, with each having some areas on the upper end of the Moderate rating. The definition of Moderate states that human triggered avalanches are possible, so in these areas careful route finding is critical. Other gullies in Huntington also carry the Moderate rating today and although they didn't receive the new snow deposition of the aforementioned gullies in the direct lee, they do hold instabilities to watch out for.

In either Ravine, a snowpack concern to remember is newer slabs have loaded over lighter density slab and unconsolidated loose snow in many areas. This creates weakness at the interface between the two layers as the lighter density snow struggles to keep the heavier snow above in place. This scenario is what we have been referring to as "touchy" over the past several days.

Early season conditions produce tremendous variability in snow stability. It's critical that you keep a focus on these differences as you travel through the terrain. You may find hard stable snow for the first half of your climb and then what appears to be out of no where you're in 24" (60cm) of slab. Constantly re-evaluate snow stability and your route. With how the Ravines have shaped up over the past few days since the storm this will be a real concern this weekend. Pay attention to the pockety nature of the mountain's instabilities. Remember that it isn't the size of the avalanche that counts, it's the consequences.

Go to tuckerman.org tonight for the season's first Friday posting of the 'Weekend Update'. Jeff will fill us in with any updates concerning today's field observations and how weekend weather may affect the Ravines. Remember, snow stability assessment and avalanche rescue skill are perishable. You must practice, PRactice, PRACTice, PRACTICE!!! Your life, and those in your group, depends on it! If buried, your life is in the hands of your partner, make them hone their rescue skill. We have all the avalanche courses offered in the valley this winter on our website.

Please Remember:
•   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.
 
•   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.
 
•   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
(603) 466-2713 TTY (603) 466-2856
 
This is the Official Tuckerman Ravine website.  Occasionally the remoteness of Tuckerman Ravine, weather, or communication problems prevent the website from being updated immediately.  Check the date, and if it is not the most recent, you can also call the National Forest Service's 24 hour avalanche hotline at (603) 466-2713 (ext. 4)

Avalanche Advisory Archives.

United States Avalanche Danger Descriptions.

Échelle Canadienne de risque d’avalanche.

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