Good Morning. This is Alex Marienthal with the Gallatin National Forest Avalanche Advisory issued on Sunday, January 15th at 7:15 a.m. Today’s advisory is sponsored by Bridger Bowl and Montana State Parks. This advisory does not apply to operating ski areas.
Temperatures this morning are in the teens F under clear skies. Wind is westerly at 5-15 mph with gusts of 15-25 mph. Today will be sunny with temperatures in the 20s F. Wind will be 5-15 mph out of the west to southwest. Clear and dry weather will continue into to Tuesday. Wind speeds will increase Monday night and there is a chance for light precipitation Tuesday night.
Cooke City Madison Range Southern Gallatin Range
Lionhead area near West Yellowstone
Over the last three days the mountains have not received any new snow and wind has been light. Without recent loading the snowpack has adjusted to the weight of last week’s storm. However, weak facets below 2-4 feet of recent snow make large avalanches possible to trigger. An avalanche observed yesterday on Sheep Mountain near Cooke City shows the potential size and character of avalanches today (photo).
Large natural avalanches occurred last week near Cooke City during and immediately after 3-4 feet of snow fell. These slides likely failed on weak facets buried below the recent storm snow. Many of these avalanches propagated wide and ran into flat terrain (photo, photo, video). In the mountains near Big Sky and West Yellowstone weak facets are buried below 2-3 feet of last week’s storm snow. After the storm, natural avalanches were observed on Fan Mountain near Big Sky and a snowmobiler in the Lionhead area near West Yellowstone triggered two slides from flat terrain below (photo). Yesterday, riders near West Yellowstone experienced a collapse in low angle terrain and found unstable test results below the recent snow (photo).
Eric was at Buck Ridge yesterday, and I was at Taylor Fork on Friday and Beehive Thursday. We did not see recent avalanche activity and Eric witnessed a stable snowpack yesterday (video). However, I found unstable test results on facets below the recent snow in both places (photo, video). These tests are indicators that avalanches are possible to trigger. The tricky part is many slopes are stable and signs of instability are scarce. Travel cautiously in and below avalanche terrain and carefully evaluate the snowpack before committing to steep slopes. Large avalanches are possible to trigger today and the danger is MODERATE.
Bridger Range Northern Gallatin Range
The mountains near Bozeman received the least amount of snow last week and avalanche activity has been minimal. Small slides confined to new snow and wind slabs were observed during the storm last week and these instabilities have subsided. I toured north of Bridger Bowl yesterday and found a snowpack full of sugary, weak snow. Without a cohesive slab over this weak snow avalanches are unlikely.
The avalanche danger today is LOW. Watch out for unstable snow in isolated areas. These areas may exist where wind formed slabs over weak facets. Remember, small slides have high consequences above cliffs and trees.
I will issue the next advisory tomorrow morning by 7:30 a.m.
We rely on your field observations. Send us an email with simple weather and snowpack information along the lines of what you might share with your friends: How much new snow? Was the skiing/riding any good? Did you see any avalanches or signs of instability? Was snow blowing at the ridgelines? If you have snowpit or test data we'll take that too, but this core info is super helpful! Email us at mtavalanche@gmail.com or leave a message at 406-587-6984.
Month of January: Montana Ale Works has chosen the Friends of the Avalanche Center as January's "Round It Up America" recipient. Every time you round-up your bill the change gets donated to the Friends. Pennies equal dollars!
King and Queen of the Ridge, Saturday, February 4th. A Hike and Ski/Ride-a-Thon fundraising event to support the Friends of the Gallatin National Forest Avalanche Center. Register with Bridger Bowl HERE, make pledges HERE.
BOZEMAN
Tuesday, January 17, Avalanche Center Forecaster’s Social at Montana Ale Works. A small-plate fare and beer tasting fundraiser for the Friends: $40.00/person; 2 seatings (5:30 p.m. and 7:00 p.m). Get your tickets HERE.
Evenings 18-19 January, field 21 or 22 January. Introduction to Avalanches with Field Course, 7-9:30 p.m. at MSU Sub Ballroom B. Sign up HERE.
COOKE CITY
Weekly rescue training and snowpack update, 6-7:30 p.m., The Antlers Lodge on Friday, field location Saturday TBA.
BIG TIMBER
Tuesday, January 17, Avalanche Awareness, 6-7:30 p.m., Sweet Grass County High School.