Good morning. This is Eric Knoff with the Gallatin National Forest Avalanche Advisory issued on Sunday, January 3, at 7:30 a.m. Today’s advisory is sponsored by Yellowstone Arctic Yamaha and Yamaha Motor Corp in partnership with the Friends of the Avalanche Center. This advisory does not apply to operating ski areas.
This morning, mountain temperatures range from the mid-teens to mid-20s F under clear skies. Winds are increasing out of the S-SW with gusts around Big Sky and Hyalite blowing over 30 mph. Today, a southwest flow will user in a few high clouds, but conditions will remain dry. Winds will continue to blow 15-30 mph out of the S-SW. High pressure remains over the area for the next few days, but the pattern begins to change by mid-week. With a little luck we’ll see some snow falling by Wednesday or Thursday.
Bridger Range Madison Range Gallatin Range
Lionhead area near West Yellowstone Cooke City
It has now been over a week since the snowpack has been put under stress by any type of loading event. This is helping the avalanche danger trend towards stability, meaning the likelihood of triggering a slab avalanche is decreasing. However, weak facets near the ground continue to make up the foundation of the snowpack, which is a major red flag (snow pit).
As long as facets exist in the pack it’s difficult to trust any steep slope. Recent avalanche activity in the northern Madison and Gallatin Ranges along with the mountains around Cooke City is a clear indicator that human triggered avalanches remain possible (video, video, photo page). With this type of deeper instability, multiple skiers or riders can hit a slope before someone finds a weak spot or trigger point. Avoid rock outcrops, cliff bands and steep convex rolls; places where it will be easiest to impact and collapse the weak layer. If an avalanche is triggered, it will likely fail at the ground producing a large and dangerous slide. This problem can be avoided completely by sticking to slopes less than 30 degrees in steepness that aren’t connected to steeper slopes above.
A secondary concern today will be wind slabs formed by south-southwest winds. This problem will be confined to upper elevation, leeward slopes. Watch out for thick, rounded wind drifts and avoid steeper terrain where these features are present.
Today, heightened avalanche conditions exist on specific terrain features. For this reason, human triggered avalanches are possible and the avalanche danger is rate MODERATE.
I will issue the next advisory tomorrow morning at 7:30 a.m. If you have any snowpack or avalanche observations to share, drop us a line at mtavalanche@gmail.com or leave a message at 587-6984.
EVENTS and AVALANCHE EDUCATION
A complete calendar of classes can be found HERE.
Bozeman: January 6, Women’s Avalanche Awareness and Beacon 101, Beall Park, 6-8 p.m.
January 8 and 9, Companion Rescue Clinic, REI, Fri 6-8p.m., Sat 10a.m.-2p.m.
January 13, 1hr Avalanche Awareness, REI, 6-7:30 p.m.
West Yellowstone: January 9, 23, and 30, 1hr Avalanche Awareness, West Yellowstone Holliday Inn, 7-8:30 p.m.
Livingston: January 14, 1hr Avalanche Awareness, Neptune’s Brewery, 6-7:30 p.m.
Cooke City: January 16, 1hr Avalanche Awareness, Visitor’s Center, 6-7:30 p.m.
January 30, Companion Rescue for Snowmobilers, https://www.ticketriver.com/event/18078
Dillon: January 19, 1hr Avalanche Awareness, UM Western Library, 6:30-8 p.m.
January 23 and 24, Intro to Avalanches w/ Field Course, https://www.ticketriver.com/event/18441
ASMSU Intro to Avalanches w/ Field Course
January 20, 21 and 23 or 24: https://www.ticketriver.com/event/16861
The workshops will be held on Wednesday and Thursday evenings, with a field course on either Saturday or Sunday. Different topics will be presented each evening. Topics include: avalanche terrain recognition, the effect weather has on avalanche hazard, the development of the mountain snowpack, decision making skills, and basic search and rescue procedures.
Advanced Avalanche Workshop w/ Field Course
January 27, 28, and 30: https://www.ticketriver.com/event/16862
Course content includes: snowpack metamorphism, the mechanics of avalanche failure and fracture, and decision-making. Different topics are covered each evening session. The field session includes snowpack analysis and avalanche rescue scenarios.