Avalanche Advisory for Tuckerman and Huntington Ravines
Posted: 8:04 a.m., Thursday, January 21, 2010

Tuckerman and Huntington Ravines have HIGH avalanche danger today. Natural and human triggered avalanches are likely on a variety of slope angles and aspects. Unstable slabs are likely. Travel in avalanche terrain is not recommended. The only exceptions to this are the Lower Snowfields in Tuckerman and the Escape Hatch in Huntington which have CONSIDERABLE avalanche danger. Natural avalanches are possible and human triggered avalanches are probable. Unstable slabs are probable in steep terrain. Be increasingly cautious in steeper terrain. And lastly the Little Headwall has MODERATE avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. Use caution in steeper terrain.

We certainly haven't been walloped this week, but the skies have been leaking snow since the weekend giving us a 4 day total of about 8.5" (21.5cm). A consistent inch or two a day can really sneak up on you if you're not paying attention to the mountain's history so try to visualize this recap. On Monday morning the mountain received a blanket of 4" (10cm) of 7% snow with winds between 15-30mph. Each morning since we have picked up another 1-2" (2.5-5cm) with winds at or below Monday's velocities. Then yesterday wind speeds were forecasted to hit 50+mph from the NW by dusk which we expected to start moving this blanket of snow down into avalanche terrain. The models were ahead of actual weather so wind speeds didn't really increase until the overnight into eary this morning. Currently they are gusting between 50-55mph (80-88kph), from the WNW (296 degrees), and moving the aforementioned snow into the steep slopes of the Ravines. Most of this week's snow was low density between 4-8% and is having no problem becoming airborne again due to current wind speeds. This is packing slabs into the protected lee areas with a S and E facing component. I would also expect cross loading of other terrain. In addition to this loading problem new slabs are building on the unconsolidated blanket of low density snow I was just discussing. This will make for an generous series of potential weak layers as the spectrum of densities differ around our forecast areas. So... based on the wind forecast of 50+mph we believe natural avalanches are likely today due to soft slabs being created on unconsolidated snow. In addition to natural releases human load through skiing, riding, or hiking will provide an easier trigger for today's touchy slabs.

If you plan on being up here tomorrow I would anticipate a mosaic of avalanche danger depending on today's avalanche activity. It looks like nice weather will prevail until late into the weekend. Weather models are indicating a chance of a storm Sunday night into Monday and it may be a bit on the warm side.

The Lion Head Winter Route is open. It is a steep route and an ice axe and crampons are recommended for safe travel. The Sherburne Ski Trail is in good shape with new snow.

Please Remember:
•   Natural events such as avalanches are impossible to accurately predict 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 higher summits forecast.
 
•   For more information, contact the U.S. Forest Service Snow Rangers, the AMC at the Pinkham Notch Visitor Center or Hermit Lake Shelters or the HMC caretaker at the Harvard Cabin. A new avalanche advisory will be issued tomorrow and this advisory expires 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.

Back to the Mount Washington Avalanche Center Homepage