Apr 022013
 

This advisory expires at 12:00 midnight tonight.

Tuckerman Ravine has HIGH and CONSIDERABLE avalanche danger today. The Lip and Center Bowl have High avalanche danger. Natural avalanches are likely and human triggered avalanches are very likely. Travel in avalanche terrain is not recommended. All other areas have Considerable avalanche danger. Natural avalanches are possible and human triggered avalanches are likely.  The Little Headwall is the only exception to these ratings, as it has Low avalanche danger.

Huntington Ravine has CONSIDERABLE avalanche danger. Natural avalanches are possible and human triggered avalanches are likely. Conservative decision making is essential today.

This is not a belated April Fools joke…there is a significant amount of new snow up at Hermit Lake that’s been falling since yesterday afternoon. Current conditions are nearly perfect for loading cold slabs into most forecast areas of both Tuckerman and Huntington. Thick 10% density snow is currently falling at a rate of about 1 cm per hour and winds are from the WNW at 50-60mph (80-95kph). We’ve measured 4″ (10cm) of snow at Hermit Lake, so if the current snowfall rates keep up we’ll have perhaps 7″ (18cm) or more of snow to be transported into the ravines today. The take-home message for today is this: traveling in avalanche terrain on leeward slopes is a dangerous proposition. This includes traveling into the floor of Tuckerman, whether it’s just to take a look around or to access the Little Headwall. The best way to get to the Little Headwall today would be to drop in below the first aid cache.

We have a couple forecast areas posted at High danger today. This is because of their leeward position on the mountain, the large expanse of the Bigelow lawn above them, the steepness of the slopes, and their historic tendency to produce avalanches under these conditions. Areas directly adjacent to them, i.e. the Sluice and Chute, will be pushing the limits of a Considerable rating. This means that the potential for naturally triggered avalanches is moving from “possible” towards “likely.” Other locations posted at Considerable are also going to sit solidly in the range, with increasing hazard as snowfall continues throughout the day. If I were looking to travel in Tuckerman or Huntington today, I would have concerns about every single forecast area. Even in the Lower Snowfields I’d be head’s up, with steep open slopes under the rock buttresses as well as the threat looming from the Duchess and Dead End Gully. The Little Headwall is a different beast. Avalanche danger is Low but there are open water holes that are being hidden by blown-in snow.

In Huntington, my concerns also extend to all forecast areas. However, the greatest concerns are in Odell, Pinnacle, Central, and Yale. These sit in the direct lee, so they’re get a lot of loading. Adjacent locations will also receive loading, though maybe not to the extent of those in the direct lee.

We’ll have to wait and see how this whole event plays out. If you’re thinking about where to ski, you might want to know that there was only a dusting of snow at Pinkham this morning. So while there is plenty of fresh snow at the top of the Sherburne, expect it to transition to dust on crust as you descend. Expect avalanche danger to remain elevated Wednesday due to continued upslope snowfall, wind, and cold temperatures through tonight and tomorrow.

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 at 8:00a.m., April 2, 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

2013-04-02 Printable

 Posted by at 7:55 am