Good Morning. This is Alex Marienthal with the Gallatin National Forest Avalanche Advisory issued on Saturday, December 2nd at 7:00 a.m. Today’s advisory is sponsored by Bridger Bowl and Knoff Group Real Estate. This advisory does not apply to operating ski areas.
NEW THIS SEASON: Regional Conditions Pages. Links at top of advisory and in the ‘advisory’ dropdown menu.
Last night the mountains got 2” of new snow near Cooke City and no new snow elsewhere. This morning temperatures are teens to low 20s F and wind is southwest-west at 10-20 mph with gusts to 30 mph. Cloud cover will increase today with light snow showers, temperatures in the high 20s F, and wind at 15-25 mph out of the west-southwest. The mountains will get 2-4” of new snow by morning with more expected through tomorrow night.
The snowpack throughout our advisory area is generally stable and lacks widespread persistent weak layers (snowpits). With no more than a couple inches of new snow today avalanches are not likely. Wind slabs that formed from new snow and wind earlier in the week have gained strength and are hard to trigger today. However, these slabs may still be found near ridgelines, below cornices, or along the edges of gullies. Approach this terrain with caution and consider the consequences of being caught in any size slide. Very small fresh wind slabs may form by this afternoon if a few inches of snow fall today.
Cornices are impressive in size right now and hang far off the leeward edge of ridgelines (photo, photo). These massive blocks of snow could break under the weight of a skier or snowmobiler. Though not likely, a cornice could be the perfect trigger for a large avalanche like the one triggered by Big Sky Patrol a couple days ago (photo, photo, photo). Travel far back from the leeward, corniced edge of ridgelines and minimize time on slopes below cornices.
The massive avalanche triggered by Big Sky patrol shows the isolated potential to trigger a deep slab on old, weak snow from September and October. This type of avalanche is not likely, but the right trigger in the right place today might trigger a slide. Practice safe backcountry travel. Carry rescue gear and expose no more than one person at a time to avalanche terrain. Today, a generally stable snowpack and minimal recent snow makes the avalanche danger LOW.
If you get out and have any avalanche or snowpack observations to share, drop a line via our website, email (mtavalanche@gmail.com), phone (406-587-6984), or Instagram (#gnfacobs).
Get Avalanche Smart Video Series
The Avalanche Center and Friends group work hand-in-hand to bring you daily avalanche information and education. This last video in series of 4 shows how we create a culture of being safe in the backcountry: Get Avalanche Smart – Episode 4: The GNFAC
Upcoming Avalanche Education and Events
BOZEMAN
Dec. 6, Avalanche Awareness, 6-7:30 p.m. at REI Bozeman
Dec. 7, Avalanche Awareness and Beacon Practice, 6-8 p.m. at Beall Park, Bozeman
Dec. 13, Avalanche Awareness, 6:30-8 p.m. at Gallatin Valley Snowmobile Association, 4-Corners
Jan. 12 and 13, Companion Rescue Clinic, Info and Register
Jan. 17, 18 and 20 or 21, Introduction to Avalanches w/ Field Day, Info and Register Here
Jan. 24, 25 and 27, Advanced Avalanche Workshop w. Field Day, Info and Register Here
Feb. 9 and 10, Companion Rescue Clinic, Info and Register
HELENA
7 December, Avalanche Awareness, 6-7:30 p.m. at Basecamp, Helena
WEST YELLOWSTONE
Dec. 14 and 15, Snowmobiler Introduction to Avalanches with Field Course, Info and Register Here
COOKE CITY
8 and 9 December, Current Conditions and Avalanche Rescue, 6:30-7:30 p.m. Friday @ the Super 8, and anytime between 10-2 on Saturday @ Lulu Pass road.
Check out our playlist of videos from last April’s Professional Development Workshop. The topic of the day was “Avalanche Science, Avalanche Stories”.