Good morning. This is Mark Staples with the Gallatin National Forest Avalanche Advisory issued on Saturday, December 13 at 7:30 a.m. Today’s advisory is sponsored by Grizzly Outfitters in partnership with the Friends of the Avalanche Center. This advisory does not apply to operating ski areas.
Overnight no snow fell. Winds calmed and this morning were blowing 5-10 mph gusting to 25 from the SW to SE except in Hyalite Canyon where they continued blowing 30-50 mph. Temperatures this morning were in the high 20s to low 30s F. Today temperatures should drop and moisture will move over the area as winds shift a little more westerly. By the end of the day most places will have temperatures in the mid 20s F and 1-3 inches of snow.
Bridger Range Gallatin Range Madison Range
Lionhead area near West Yellowstone Cooke City
In most areas the snowpack is only 1-2 feet deep and has weak facets in the bottom 4-8 inches. These facets have gained strength on some slopes, especially ones at low elevations, but on many slopes and in many avalanche starting zones they remain weak as Eric and I found on Lionhead near West Yellowstone yesterday (photo, video) and I found on Saddle Peak on Thursday (photo, video). Near Cooke City the snowpack is generally 3-4 feet deep but has a similar layer of facets.
Are conditions unstable? In most avalanche starting zones, the odds of hitting rocks and damaging your skis or snowmobile are much higher than triggering an avalanche. Despite weak snow near the ground, many slopes are relatively stable because they have been sitting long enough without the added weight and stress of new snow to make them unstable.
But (there’s always a “but”), avalanches are still possible. An avalanche near Cooke City on Thursday (photo1, photo2) and some reports of collapsing and cracking of the snowpack tells us so. This is why we carry avalanche rescue gear, only expose one person at a time, and evaluate every slope.
Triggering an avalanche is hard to do on many slopes and easy on some. It’s difficult to tell the difference, so make sure to stop and look for recent avalanches, put your shovel in the snow, look at the layers, perform stability tests, and consider the consequences of an avalanche on every slope. For today, the avalanche danger is rated MODERATE
Now’s a great time to practice your avalanche rescue skills. Watch this 4 minute video on how to perform a rescue and how to practice.
Eric 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.
AVALANCHE EDUCATION and EVENTS
Take a look at our Education Calendar for all classes being offered.
Avalanche Awareness (Free 1-hour), Sunday, December 14, 3 p.m. at Redline Sports, Butte
Fundraiser at Katabatic Brewing, Tuesday, December 16, 4-8 p.m., Livingston
Avalanche Awareness and Beacon Practice, Wednesday, December 17, 6:30-8:30 p.m. at Beall Park, Bozeman
Avalanche Awareness (Free 1-hour), Thursday, December 18, 6 p.m. at the Yellowstone Association, Gardiner
Snowmobiler Introduction to Avalanches with Field Course
West Yellowstone: Dec 18 and 19, 2014: https://www.ticketriver.com/event/12955
Five hours of lectures are followed by a full day field course. Topics covered include: avalanche terrain recognition, the affect weather has on avalanche hazard, the development of the mountain snowpack, decision making skills, and basic search and rescue procedures.