Expires at midnight, Wednesday 3-20-2013
Tuckerman and Huntington Ravines have HIGH avalanche danger. Natural avalanches are likely and human triggered avalanches are very likely. Very dangerous avalanche conditions exist. Travel in avalanche terrain is NOT recommended.
As of midnight on this first day of “Spring” the summit of Mount Washington received 16” (41cm) of new snow with an average density of 6.2%. Since then it’s been lightning up a bit, but upslope snow continues to fall which will likely bring us close to 20” by the time it all shuts down. This storm is closer to what I remember over the years as a classic compared to the recent events over the past couple of seasons. The storm came in dropping its snow from the SE and the SSE with moderate winds, which is typical, but then immediately wrapped to the NW and W with an increased wind velocity. Most of our storms this season have lingered from the NE or N for a day robbing us of great snow loading events, but not this one!
Winds from the NW shifting to the W will increase through the day reaching 80mph late this afternoon. This will move large volumes of snow into all our forecast areas through direct and cross loading. Wind speeds will likely peak between 6pm and 4am before dropping through tomorrow and becoming light. In addition to all the snow available for transport from alpine zones, upslope snow will give us some more from the sky with 2-4” today and 1-4” tonight and tomorrow. I expect widespread natural avalanche activity on a variety of slope angles and aspects, some of which will be quite large. The largest of which will come from the area from the Sluice through the Center Headwall of Tuckerman. It is an excellent day to take advantage of lower mountain trails or lift serve skiing and riding to avoid avalanche terrain. The Sherburne ski trail should be in very good shape this morning before winds start sculpting the upper half. The Gulf of Slides ski trail should also be enjoyable, but be sure to avoid the obscured avalanche paths that historically cross the trail in its upper reaches.
Avalanche activity today and high scouring winds overnight will both likely give us a whole different scenario tomorrow. Be sure to read Thursday morning’s advisory before venturing into avalanche terrain.
- 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 8:20 a.m. 3-20-2013. A new advisory will be issued tomorrow.
Christopher Joosen, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856