Good morning. This is Eric Knoff with the Gallatin National Forest Avalanche Advisory issued on Sunday, December 30 at 7:30 a.m. Today’s advisory is sponsored by Knapp Sacks and Lone Peak Brewery. This advisory does not apply to operating ski areas.
Overnight a trace of new snow fell in the mountains. An additional 1-2 inches is possible by this afternoon. Currently, temperatures are in the single digits F and winds are blowing 5-10 mph from the WSW. Temperatures will warm into the teens today and winds will switch to the WNW blowing 5-15 mph. No snow is expected tonight through tomorrow.
Bridger Range Madison Range Gallatin Range
Lionhead area near West Yellowstone Cooke City
Skiers and riders have been observing a generally strong snowpack throughout our forecast area. A large holiday crowd has been pushing the envelope with little activity to report. The problem with this situation is that the more avalanche terrain people cover, the higher the probability becomes of someone triggering a slide (photo, photo, video).
The second problem is people are becoming less focused on safe backcountry travel. Over the past week I’ve observed numerous situations where multiple people are riding a slope at the same time. This type of behavior increases the chance of an unfavorable outcome if an avalanche is triggered. Whether skinning up, skiing down or pushing the throttle, safe backcountry protocol is essential.
Today, triggering an avalanche will require finding the right spot on the right slope. In many cases, multiple skiers or riders can hit a slope before someone impacts a buried weak layer. Steep, rocky terrain, specifically where the snowpack is less than 3 feet deep will be areas susceptible to producing an avalanche. Taking time to assess the snowpack and terrain before committing to steep slopes is a good habit to get into.
NEW WEAK LAYERS FORMED
Periods of cold, clear weather have turned the top few inches of snow into weaker, small grained facets. These near surface instabilities do not exist on all slopes, but have been observed throughout our forecast area. This layer is now capped by a few inches of new snow. It is not deep enough to be a major avalanche concern yet, but it’s something to look for since these layers tend to persist.
Today, human triggered avalanches 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.
Thursday, January 3, 6:00 p.m., 1-hour Avalanche Awareness lecture at 406 Brewing Company, Bozeman.
Tuesday, January 8, 7:00 p.m., 1-hour Avalanche Awareness at Big Timber High School.
Wednesday, January 9, 6:30 p.m., 1-hour Avalanche Awareness at REI, Bozeman.
Thursday and Saturday, January 10 and 12, Rescue Clinic. Thursday at 6:00 p.m. at REI, Bozeman and Saturday at 10 a.m. in the field, location TBD. For more info and to register go http://www.rei.com/event/47692/session/64126
Saturday and Sunday, January 12 and 13, Snowmobiler Introduction to Avalanches with Field Course. For more information and to sign up: https://www.ticketriver.com/event/4979-snowmobiler-introduction-to-avalanches-w-field