This advisory expires at 12:00 midnight, February 28, 2013.
Tuckerman Ravine has Considerable avalanche danger. Lobster Claw, Right Gully, the Sluice, the Lip, the Center Bowl, the Chute, Left Gully, Hillman’s Highway, and the Lower Snowfields have Considerable avalanche danger. Natural avalanches are possible and human triggered avalanches are likely. The Little Headwall has Moderate avalanche danger. Natural avalanches are unlikelyand human triggered avalanches are possible.
Huntington Ravine has Considerable avalanche danger. Natural avalanches are possible and human triggered avalanches are likely in all forecast areas of Huntington Ravine. Careful snowpack evaluation, cautious route-finding and conservative decision making are essential.
Well, our snowpack is turning around after a lacklaster early winter. In addition to the obvious economic benefit to the area and the payoff for all the funhogs in the area, snow geeks and avalanche buffs on Mount Washington will be treated to another round of avalanche activity. Almost 13″ of snow fell during this storm and though the snow will end in the valleys today, the mountains will receive another 2-4″ today, 1-3″ tonight, and 1-3″ tomorrow for a grand total somewhere in the neighborhood of 17-19+”. Wind direction will be shifting from the East to the North or Northwest through the day which will serve to lightly load areas which may have been more scoured than loaded by the high winds that the mountain experienced last night. In Huntington Ravine these high winds, which gusted to 95 mph and blew steadily in the high 60’s mph, moved snow around in the east facing gullies like Central and Yale and cross loaded areas with a north or south facing aspect as well as lee terrain features. With winds shifting around towards the north, gullies and terrain features in both Ravines with less snow due to avalanches or wind transport will reload a bit today. Although winds will be light, blowing 15-30mph, some loading is expecting high in typical start zones. This will add more instabilities and issues to areas already meeting a Considerable rating. Anticipate some slopes in the direct lee of N and NW winds to move towards the upper end of the rating if we pick up multiple new inches today.
There is alot of information critical to determine where and when a natural avalanche is going to occur. Much of this information may be denied to mountain travelers today due to low visibility conditions with only brief and unreliable “windows” in which to make assessments. Venturing into either ravine to get close enough to assess which avalanche paths have already slid will be sketchy and coming from the top creates hazards for folks who may be on the floor. Avalanche slide paths, which are more filled in now due to recent avalanche activity, will allow avalanches to run further out onto the floor of the Ravines making travel into those areas a roll of the dice. Assessing the depth and area of slabs, locating and avoiding trigger points, coupled with new precipitation and windloading will challenge the most experienced avalanche practitioner today.
- 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 8:45a.m., February 28, 2013. A new advisory will be issued tomorrow.
Frank Carus, Snow Ranger
USDA Forest Service
White Mountain National Forests
(603) 466-2713 TTY (603) 466-2856