Avalanche Advisory for Wednesday 4-17-2013

This advisory expires at 12:00 midnight.

Tuckerman and Huntington Ravines have LOW avalanche danger. Natural and human triggered avalanches are unlikely.

It’s looking like today will turn out to be a pretty good day on the mountain, but you don’t need to rush uphill to get the goods before they’re gone. Instead, re-read the weather forecast, have a second cup of coffee, and wait for winds to diminish and the snow to soften up. Last night Mt. Washington received a little under a half inch of rain, which was followed by freezing temperatures up in the ravine. This is a great way to stabilize the snowpack and drop avalanche hazard to the low end of low. While it helps a lot with snow stability, it creates other problems that you’ll need to be prepared for, such as:

  1. Long sliding falls. For many people, steep icy slopes are more manageable once the skis are on their feet. However, you’ve got to climb up one way or another. We highly recommend bringing an ice axe and crampons for safety on the way up, especially on days like this where the snowpack will start out very hard and icy. Later today south-facing slopes will hopefully soften up and make this less of a concern.
  2. Falling ice. The annual process where all the ice that formed during the winter crashes down into the Bowl has begun. Rain events like last night and sun and warming like we’ll see today make the problem worse. We know it will happen, the question is exactly when. It’s your job to be aware of the hazard and have a plan in mind for what you’ll do when you see that dishwasher sized chunk of ice rocketing at you. Lunch Rocks and the floor of the ravine are directly in the path of falling ice.
  3. Crevasses. We have yet to see much of this problem yet, but it’s going to start to make an appearance soon. Warm temperatures cause the snowpack to creep downslope, which opens up deep cracks in the snowpack each season. Many times these can’t be seen from above them. The best way to know about this hazard is to climb up your intended decent route.
  4. Undermined snow. Right now this issue is mostly found in the streambed leading out of the ravine and on the Little Headwall. The Little Headwall has a large open hole in the steepest part of the route.  This hole has grown in the last couple days, and is threatening to collapse further. The same can be said for the snow bridges in the streambed above the Little Headwall. Use caution if you decide to ski out from the Bowl. Hiking out on the trail is a faster and safer option.

We’ve been fielding a lot of questions lately about overall conditions in the ravine. Generally we’ve got good snow coverage right now. It’s certainly better than this time last season. Most runs are filled in from top to bottom. Remember that snow quality changes quickly though. We currently have the Sherburne open to the bottom, it’s full of moguls, bare patches and very thin spots. A few days of warmth and rain can quickly eat away at the remaining snow down low, forcing us to hang the “trail closed” rope at various points. We’ll do our best to keep you posted for changes when they happen. Also of note is the 2013 Tuckerman Inferno is this Saturday, hosted by Friends of Tuckerman Ravine.

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 8:00 a.m., April 17, 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

2013-04-17 Printable