Good morning and happy Valentine’s Day. This is Eric Knoff with the Gallatin National Forest Avalanche Advisory issued on Sunday, February 14, at 7:00 AM. Today’s advisory is sponsored by Grizzly Outfitters in partnership with the Friends of the Avalanche Center. This advisory does not apply to operating ski areas.
Over the past 24 hours the Bridger Range picked up 6-8 inches of high density snow. The rest of the advisory area picked up 3-6 inches. At 4 a.m. snow is tapering off and temperatures range from the mid-teens to low 20s F. Winds are blowing 15-30 mph out the W-SW with ridgetop gusts pushing 40 mph. Today, snow will redevelop in the mountains as moisture continues to be ushered into the area on a northwest flow. Winds will shift from the SW to the NW during the day and temperatures will warm into the mid to upper 20s F. Snow accumulations of 1-3 inches can be expected during the day with an additional 2-3 inches falling tonight into tomorrow.
Bridger Range Madison Range Gallatin Range
Lionhead area near West Yellowstone Cooke City
The Bridger Range got blasted with a quick but heavy dose of snow yesterday then again overnight. What’s impressive about the latest round of snow is the high moisture content. Brackett Creek Snotel site is recording .8 inches of SWE in the past 24 hours. The rest of the advisory area picked up .3-.4 inches of SWE.
Today, the primary avalanche concern will be wind slabs. Moderate to strong winds out of the west-southwest and northwest will form dense slabs on leeward slopes. Due to the high moisture content of the new snow, these fresh slabs will be thick and stubborn. While they might take some coaxing to release, they have to potential to break deeper and wider than you might expect. Today, avoiding wind loaded slopes will be the best way to avoid triggering a slide.
Outside of new snow instabilities, facets buried mid pack and near the ground remain a concern (photo, video). Yesterday, I toured in Beehive Basin and got unstable results in stability tests on a layer of facets 40 cm off the ground (video). This is a good reminder that we’re not out of the woods with the deep slab avalanche problem. A new layer to look out for will be a layer of surface hoar. This layer does not exist in all areas, but it was observed on all aspects and elevations in the mountains around Cooke City (photo). It could easily exist on other slopes across the advisory area. It will be something to watch out for as the mountains get more snow over the next few days.
Today, human triggered avalanches are likely on wind loaded slopes steeper than 35 degrees which have a CONSIDERABLE avalanche danger. All other slopes have MODERATE avalanche danger.
I will issue the next advisory tomorrow morning by 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.
Darren Johnson Avalanche Education Memorial Fund
The National Avalanche Foundation set up an education fund in memory of Darren Johnson, the Yellowstone Club ski patroller who died in an avalanche on January 19. You can check out details and make donations here: http://www.mtavalanche.com/sites/default/files/NAF%20Darren%20Johnson%20Memorial%20Fund.pdf.
EVENTS and AVALANCHE EDUCATION
A complete calendar of classes can be found HERE.
West Yellowstone: Saturday, February 20, 7-8 p.m., 1-hr Avalanche Awareness for Snowmobilers at the Holiday Inn.
Bozeman: Wednesday, February 24, 6-7 p.m. 1 hr Avalanche Awareness, Roskie Hall, MSU