Expires tonight at midnight December 28th 2012.
Tuckerman and Huntington Ravines have CONSIDERABLE avalanche danger today. Natural avalanches are possible and human triggered avalanches are likely. Careful snowpack evaluation, cautious route-finding, and conservative decision-making are essential.
It’s pretty incredible to see firsthand how quickly Mt. Washington can evolve into a wintery landscape. As of two weeks ago, the summit had recorded only 6″ (15cm) of snow for the month of December. After yesterday’s storm, that total has soared to 63″ (160cm). Yesterday’s storm was a good one, dropping almost 16″ (40cm) on the summit and about the same at Hermit Lake. The exact numbers are disputable, because strong winds have drifted snow into our snow study plots lower on the mountain and forced the Observatory to partially estimate their totals. Without a doubt though, a lot of snow fell yesterday. Early in the storm winds were generally from the east, increasing towards 100mph (162kph) and gusting even stronger. They did subside some in the afternoon before making a swing around to the NW and ramping up again this morning.
Currently, winds are howling at Pinkham and Hermit Lake, pushing around a lot of snow and generally making life uncomfortable for those gearing up in the parking lot. Blowing snow is the chief concern for today and is driving the Considerable rating. What fell yesterday with the easterly winds is being pushed right back in the direction of the ravines today. NW winds are great at loading snow into all of our forecast areas, so the number one problem you’ll face in avalanche terrain is new windslab on the surface. We are hoping that the clouds clear out enough today to actually get to look at where recent snows were deposited and hopefully see evidence of some early season avalanche activity. If you’re heading for avalanche terrain today, take some extra time to think about your route choices. The east winds may have deposited snow in unusual locations, and new loading may be changing the overall loading pattern right before your eyes.
As we move closer to the weekend, you can expect diminishing winds early on Saturday, followed by the chance for some additional snowfall later in the day as well as on Sunday. We’ll post our first Weekend Update this evening on our website, www.mountwashingtonavalanchecenter.org. Be sure to keep up to date with the latest weather information and avalanche advisory before heading up the mountain.
- 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 8:45 a.m. December 28, 2012. 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