Good morning. This is Eric Knoff with the Gallatin National Forest Avalanche Advisory issued on Monday, February 8, at 7:00 AM. Today’s advisory is sponsored by Javaman and Bountiful Table. This advisory does not apply to operating ski areas.
At 4 a.m. mountain temperatures range from the teens to mid-twenties F and skies are partly cloudy. Winds are blowing 15-30 mph out of the W-NW with the occasional ridgetop gusts pushing 40 mph. Today, unseasonably warm temperatures will produce spring like conditions. Highs will climb into the 30s and 40s under mostly clear skies and winds will continue to blow 15-30 mph out of the W-NW. High pressure remains the dominant weather pattern and temperatures look to be even warmer over the next few days.
Bridger Range Madison Range Gallatin Range
Lionhead area near West Yellowstone Cooke City
The maelstrom that took place on Saturday left very few slopes unscathed. Yesterday, Alex and his partner toured north of Bridger Bowl and found nearly every slope had been affected by the wind. Reports from Big Sky mentioned similar conditions.
In upper elevation terrain, many windward slopes have been scoured down to rock and dirt while leeward slopes have been loaded with thick, dense wind slabs. Yesterday, skiers outside of Cooke City triggered a large wind slab the broke 2-3 feet deep and 150 feet wide. The slide occurred on a S-SE facing slope and likely failed on a thin layer of small grained facets. Natural avalanches were also observed south of Bridger Bowl and in the mountains near Big Sky. This activity comes a day after many small wind slabs were triggered on Buck Ridge (photo).
Today, the lack of available snow for transport combined with warm temperatures will help recently formed wind slabs stabilize. This however does not mean the light is green on every wind loaded slope. Wind slabs still hold the potential to fail under the weight of a skier or rider and wind loaded slopes should be approached with caution.
A secondary avalanche concern is faceted layers buried mid pack and near the ground (video). These layers will be under additional stress on any slope that has been recently wind loaded. While these layers are gradually gaining strength, they must be considered before skiing or riding any steep slope. See a video that Doug Made in Bacon Rind yesterday explaining this problem (video).
Today, conditions are trending towards stability but human triggered avalanches remain possible and the avalanche danger is rated MODERATE.
Alex 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.
Bozeman, Tuesday, February 9: 1hr Avalanche Awareness for Snowmobilers, Summit Motorsports, 6-7 p.m.
Wednesday, February 10: 1hr Avalanche Awareness for Women, REI, 6-7 p.m.