Posted 9:00a.m. Thursday, December 11, 2014. Expires at 12:00 midnight Saturday, December 13, 2014 unless updated based on a change of conditions.
This is an early season GENERAL AVALANCHE ADVISORY. A new General Advisory will be issued if conditions warrant or within 72 hours of this release. General Advisories are issued when isolated areas of unstable snow may exist within the forecast areas. Forecasts using the 5-scale danger rating system will begin when snowfields and bed surfaces become more developed. Please remember that avalanche activity may occur before the issuance of a 5-scale danger rating forecast. As always, make your own snow stability assessments when traveling in avalanche terrain.
A large area of Low pressure sitting on the Maine coast will continue to send moisture laden air into our area. New precipitation will be wet snow or freezing rain for Thursday before transitioning to all snow Friday and into Saturday. Snow water equivalent is forecast to be in the range of a tenth to .15″ today (Thursday) which should fall as wet snow with some freezing drizzle and freezing fog mixed in. Over the past two days, about 12″ (30cm) of snow and mixed precipitation has fallen; 10.5″ (26cm) of snow topped by wet snow and rain on Tuesday and Tuesday night, and 1.5″ (3.75cm) mixed frozen forms, rimed pellets, ice and snow (38% density) on Wednesday and Wednesday night. This mixed bag of precipitation is continuing to enlarge and connect our snow slopes and create the bed surface for new snow and wind loaded snow coming Thursday and Friday. Be prepared to assess slopes and gullies for new slabs of wet snow which may be unstable and respond to a human trigger. Some new wind loading may occur later Thursday and into Friday as winds shift to the NW and increase in velocity. Hopefully a reasonable level of visibility will allow for some visual assessment and photos today but I will at least dig in the snow to check out the snow structure and look for signs of deeper weak layers that pre-existed the larger snowfall on Tuesday-Wednesday and resulted in a human triggered, hard slab avalanche in Diagonal Gully on Monday. Currently, our best way to post photos is on the Mount Washington Avalanche Center Facebook page so seek us out, like us and look there for photos there.
Remember that the current limited snow cover can not only produce avalanches but the existing rocky terrain can beat you up in the event of a fall or being carried by an avalanche. Now is the time to carry avalanche rescue gear, be searchable by wearing your transceiver (which is turned on, right?!) and to be prepared for full winter conditions with the proper equipment, clothing and mindset.
The Sherburne Ski Trail has been getting a good bit of ski traffic though there are still some open waterbars to avoid. If you’re heading there or to the Gulf of Slides Ski Trail, remember that it is still very early in the season. Expect abrupt waterbars, hidden rocks, and plenty of exposed vegetation.
- 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.
Frank Carus, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856