Avalanche Advisory for Sunday, 1-6-2013

Expires at Midnight Saturday 1-6-2013

Tuckerman Ravine has Considerable and Moderate avalanche danger today. The Sluice, Lip, Center Bowl, and Chute have Considerable avalanche danger. Natural avalanches are possible and human triggered avalanches are likely. Lobster Claw, Right Gully, Left Gully, and Hillman’s Highway have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. The Lower Snowfields and Little Headwall have Low avalanche danger. Natural and human triggered avalanches are unlikely.

Huntington Ravine has Moderate and Low avalanche danger. North, Damnation, and Yale gullies have Low avalanche danger. Natural and human triggered avalanches are unlikely. Watch for unstable snow on isolated terrain features. All other forecast areas of Huntington have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible.

Over the past 3 days the summit has received 6.6” (17cm) of new snow. Today’s weather forecast includes between a trace and 2” (5cm) of additional accumulation. This forecasted range can make for very different conditions based on how much actually falls. Increasing W winds (35-50mph up to 45-60mph) will load whatever snow falls into most forecast areas. Avalanche danger will be rising through the day, so you should be thinking both about stability problems leftover from earlier snowfalls as well as increasing avalanche hazard through the day with additional snowfall and wind loading.

As of this morning, most forecast areas in Huntington Ravine have a mix of scoured old surfaces and more recently deposited snow. The difference in ratings between the northern gullies and the rest is due to the degree of wind scouring that took place in Yale, Damnation, and North gullies. It’s important to remember that there may be strongly sheltered pockets within the Low danger rating that have unstable pockets of windslab. Don’t shut off your brain because these areas are rated Low! In the gullies with the Moderate rating, you’ll find more of the recently deposited snow and fewer scoured areas. When possible, stay on the hard old surfaces with lesser avalanche hazard. Remember, new snow accumulations today will cause avalanche danger to rise, so pay close attention and be ready to change your plans if you can’t safely navigate around an area of unstable snow.

Overall, Tuckerman Ravine has more avalanche hazard today than Huntington. Recent avalanche activity was noted yesterday afternoon in the center headwall and in unusual locations off Boott Spur ridge, Gully #3 and another even farther left. The Lip area was loaded up pretty well at that time, so even without new snow today I’d be calling that Considerable based on the likelihood of human triggered avalanches. Moving away from the Center Bowl and Lip, avalanche hazard begins to decrease, but expect the new snow today to be shifting the trend toward increasing danger through the day. With light snowfall thoughout the day, the rate at which danger rises will be slow but steady.

The Lion Head Winter Route is now open. This is a steep mountaineering route, and we strongly recommend bringing an ice axe, crampons, and the ability to effectively use these tools.

Please Remember:

  • 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.
  • Posted 8:20am, January 6, 2013. 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