Good Morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Wednesday, February 19 at 7:30 a.m. Gallatin County Search and Rescue in partnership with the Friends of the Avalanche Center sponsor today’s advisory. This advisory does not apply to operating ski areas.
Late last night the mountains around Cooke City and West Yellowstone picked up 2-3 inches of new snow while other areas remained dry. This morning mountain temperatures are near 20F with west to southwest winds averaging 25-30 mph and gusting 50-60 mph. Today will be cloudy, windy and snowy. Temperatures will drop into the teens and 2-4 inches of snow will fall during the day.
Cooke City
Winds have been strong in the mountains around Cooke City. At the Lulu Pass weather station, winds are gusting to 60 mph out of the southwest. Cooke City got firehosed with snow (4+” SWE) over the holiday weekend and Avalanche Warnings were in place through Monday. Wind-loaded slopes are where the acute avalanche danger lies and slopes that do not have windblown snow are only slightly better. Avalanches are breaking within the new snow and also on deeper layers of facets. What is important is not the exact location of the weak layer but the fact that avalanches are likely on slopes steeper than 30 degrees. Today’s snow and wind will keep the avalanche danger rating HIGH on any wind-loaded slope and CONSIDERABLE everywhere else.
Madison Range Gallatin Range
Lionhead area near West Yellowstone
It has been a busy time with avalanche activity. Skiers and snowmobilers have triggered avalanches catching a few parties. Avalanches are mostly sliding on a layer of facets that formed during the latter half of January during the dry spell, which are easily spotted 18-24 inches from the surface. I remotely triggered a small avalanche on Saturday near Carrot Basin (photo, video); the same day a skier triggered a wind-loaded slope at Bacon Rind (photo). On Sunday a party of three skiers was caught in an avalanche in Beehive Basin (photos, video, and accident report) and on Monday two snowmobilers were partially buried at Lionhead. Additionally, Eric saw large natural avalanches around Quake Lake (photo) and skiers got widespread collapsing and cracking above Hebgen Lake. Each of these incidents warrants a thoughtful pause. Taken together they add up to irrefutable evidence that the snowpack is unstable. I’m an optimist and believe the backcountry will slowly get better with time, but not today. Today is another day of traveling cautiously, and thus the avalanche danger is rated CONSIDERABLE on all slopes.
Bridger Range
It has been windy in the Bridger Range, especially at the ridgetops, but wind-loading is localized. Our primary avalanche concerns are pillows near the ridgeline, and gullies that have been cross-loaded from south winds. A secondary problem is the January layer of facets that is buried on a few slopes and still worth digging for. If you find it I would go somewhere else since it’s not out of the question to trigger a slide on this layer. Today the avalanche danger is rated MODERATE on wind-loaded slopes and slopes steeper than 35 degrees. All other slopes have a LOW avalanche danger.
Beehive Basin Accident Report
The Beehive Basin Accident report is posted online and can be read here: http://www.mtavalanche.com/accident/14/02/18
Mark 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
February 20, BOZEMAN: Thursday, 6:30-8:00 p.m., REI, Women’s Specific Avalanche Awareness lecture. Pre-registration is required: www.rei.com/stores/bozeman.html
February 22, BIG SKY: Saturday, 10 a.m. – 2 p.m., Beehive Basin Trailhead, Companion Rescue Clinic. In partnership with Grizzly Outfitters. Space is limited and pre-registration is required. https://ticketriver.com/event/9964
February 22, WEST YELLOWSTONE: Saturday, 7:00-8:00 p.m., Holiday Inn, 1 –hour Avalanche Awareness for Snowmobilers lecture.
More information our complete calendar of events can be found HERE.