Good morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Tuesday, January 17 at 7:30 a.m. This advisory is sponsored by Montana Import Group in partnership with the Friends of the Avalanche Center. This advisory does not apply to operating ski areas.
Mountain temperatures are six below zero this morning with ridgetop winds blowing 20-30 mph out of the west to southwest. Chilly. Early yesterday morning another inch fell near Cooke City and last night scattered showers dusted parts of the Madison Range. Winter has finally turned a corner and is poised to barrel down on us. Scattered showers today and tonight will become more sustained Wednesday and Thursday. By tomorrow morning I expect 1-2 inches in the north and 3-4 inches in the southern mountains. Today, winds will steadily increase out of the west to 40 mph as mountain temperatures warm to near 10F. Snow, wind and cold temperatures; what a concept!
The Bridger, Madison and Gallatin Ranges, the Lionhead area near West Yellowstone, and the mountains around Cooke City:
Yesterday, my partner and I skied north of Bridger Bowl to see how the snowpack was holding up with the nine inches of new, low density snow. Unfortunately, the east winds blew away half of it from the upper mountain. We did see a natural avalanche on a steep, north facing slope that ran hundreds of feet. It was only 50 feet wide, but after digging our snowpit there was no surprise what it failed on: facets. We found 1½ to 2 feet of facets that have grown into chains of depth hoar (video, snowpit). Digging reminded me of playing in a sandbox. There was not enough new snow to create a slab in most spots, but we would occasionally hit a thin wind drift which would easily crack and slide a few feet downhill. We also hit lots of rocks which were a greater personal hazard than avalanches.
Winds increased last night and will continue to strengthen today. Slopes with wind drifts will crack and possibly avalanche. A skier touring outside Cooke City got many thin wind slabs (4-6”) to crack from Sunday night’s new snow. Snowpits in the northern Gallatin Range, Beehive Basin and Buck Ridge (photo) in the northern Madison Range and Cabin Creek (snowpit) in the southern mountains are all showing facets breaking in the lower half of the snowpack, however, they are taking a lot of force and are not always fracturing clean. Even with widespread weakness the stability on most slopes is good because it is not under stress from the weight of new snow. In our advisory area natural avalanches are unlikely, although it’s still possible to trigger slides on slopes capped with a thick slab or wind drift. For today, the avalanche danger is rated MODERATE. With storms predicted this week I expect the avalanche danger will rise sharply in the coming days.
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.
Events/Education
Bozeman
20/20 Hindsight - Lessons from recent accidents. TONIGHT, January 17, 6:30-7:30 p.m. at Montana Import Group.
Introduction to Avalanches with Field Course. MSU, SUB Ballroom C, 7-9:30 p.m. Jan 25 and 26 with a field day Jan 28.
Dillon
1-hr Avalanche Awareness Lecture. TONIGHT, January 17, 7-8 p.m. at Montana Western Swysgood Technology Center, Great Room
Great Falls
1-hr Avalanche Awareness Lecture Thursday, January 19, 7-8 p.m. at Greenup Performance
West Yellowstone
1-hr Avalanche Awareness Lecture Saturday, January 21, 7-8 p.m. at West Yellowstone Holiday Inn
Billings
Snowmobiler Introduction to Avalanches with Field Course. Lectures on Tuesday, January 24 from 6-9 p.m. at Hi-Tech Motor Sports with an all day field session in Cooke City on Sunday, Jan 29. PRE-REGISTER BY JAN 23 at Hi-Tech!! Register with Sharon at 406-652-0090; hitech@hi-techmotorsports.com.