Good Morning. This is Eric Knoff with the Gallatin National Forest Avalanche Advisory issued on Sunday, December 12, at 7:30 a.m. Alpine Orthopedics, in cooperation with the Friends of the Avalanche Center, sponsors today’s advisory. This advisory does not apply to operating ski areas.
A fast moving storm dropped 2-4 inches of snow over our advisory area last night, with the exception of Cooke City which picked up 5 inches (Fisher Creek Snotel). Ridgetop winds have been blowing 15-30 mph out of the W-NW, but decrease significantly with a drop in elevation. Mountain temperatures are ranging from the mid-teens to low twenties F and will rise into the 30’s by this afternoon. Precipitation will continue through this morning with additional accumulations of 1-2 inches possible. Ridgetop winds will stay steady through the morning hours, but both winds and precipitation will decrease by this afternoon. Mostly cloudy skies and warmer temperatures will persist through tomorrow.
The Bridger, Gallatin and Madison Ranges, the Lionhead area near West Yellowstone, the mountains around Cooke City and the Washburn Range:
Yesterday, Mark rode into the Lionhead area near West Yellowstone and filled an empty hole in our forecasting data. The Lionhead was the last area we explored in detail, and what Mark found was an encouraging piece of information that ties our forecast area together. Reasonably stable snow blankets much of our advisory zone, creating a pleasure we did not experience once last season.
With the snowpack gravitating towards strength and stability, people's confidence is also becoming stronger, pushing backcountry uses deeper into avalanche terrain. As we know this situation is rarely sustainable and eventually something has to give. The combination of snow and wind over the past few days has kept the avalanche pulse beating, and the possibility of triggering an avalanche remains alive and well.
The most likely locations to trigger a slide will be in wind loaded terrain, mainly along the lee side of upper elevation ridgelines. An observer in Cooke City reported two avalanches in the Lulu Pass area that broke up to a foot deep and were most likely pockets of wind deposited snow. However, triggering a deeper slab will not be out of the question as the Moonlight Basin Ski Patrol found out on Thursday (photo). This is an evident reminder that digging to the ground and testing various layers in the snowpack is smart protocol before riding in avalanche terrain.
Today, small avalanches in specific areas; or large avalanches in isolated areas are possible and the avalanche danger is rated MODERATE.
I will issue the next advisory tomorrow morning at 7:30 a.m. If you have any snowpack or avalanche observations, drop us a line at mtavalanche@gmail.com or call us at 587-6984.
Upcoming Avalanche Education
“How Much Did It Snow?” Join Lucas Zukiewicz from the Montana Snow Survey for a FREE presentation/discussion on the SNOTEL system in SW Montana. The discussion will cover how to access SNOTEL information and interpret the data for snow and weather conditions. Tomorrow - Saturday, December 11, 7:30pm – 8:30pm at World Boards.
Avalanche Awareness for Snowmobilers in West Yellowstone Thursday, December 16th from 12 p.m. to 5 p.m (lectures), with an all day field day Friday, December 17th. For more information check out http://www.mtavalanche.com/education/classes/snowmobilers or call us at 587-6984.
1hr Awareness - Mon, December 13, 7pm – 8pm at Beall Park map
Other News
This year REI has chosen Friends of GNFAC as their charity of choice. By making a donation through REI you can help The Friends continue to support the Avalanche Center and promote avalanche education throughout southwest MT.