Good Morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Wednesday, March 8th at 7:00 a.m. Today’s advisory is sponsored by Cooke City Super 8/Bearclaw Bob’s and Bridger Bowl. This advisory does not apply to operating ski areas.
In the last 24 hours the mountains around Cooke City and West Yellowstone have gotten 8” of new snow with 3” in Taylor Fork and 1” around Big Sky and Hyalite. Winds are from the southwest to west at 20-25 mph with gusts of 40-50 at the ridgelines. Today, under cloudy skies, winds will continue and temperatures will remain in the low 20s. Snowfall will be steady in the southern mountains and become widespread tonight. By morning the southern mountains will have 6-10”, 4-6” around Big Sky and 2-4” further north.
Lionhead area near West Yellowstone Cooke City
Since Saturday evening Cooke City and Lionhead have gotten 20” of snow (2” SWE). Winds have been strong out of the W-SW and drifts are thick, dense and ready to avalanche. Eric and I rode into Lionhead and pinned the throttle multiple times to plow through whale-sized drifts. Cracks would shoot out in front of the sled and in one spot we were able to trigger a small wind-loaded slope, far below the ridge crest where triggering slides would have serious consequences (photo). As Eric says in the video, “This is bulls-eye information that wind-loaded slopes are unstable.” Even on slopes without a wind-load avalanches are possible given the steady snowfall. Outside Cooke City on Monday a skier noted the new snow avalanching (photo). With another foot of snow since then the stability has not improved. My recommendation is to avoid wind-loaded terrain, be mindful of terrain traps and remember that most avalanches occur during storms…like today. Since human triggered avalanches are likely, the avalanche danger is rated CONSIDERABLE on all slopes.
Gallatin Range Madison Range
The Gallatin and Madison Ranges have picked up 10” of snow since Sunday night. Wind has loaded slopes near the ridgelines and the Big Sky Ski Patrol successfully triggered these in the last few days. Yesterday, a skier up Lick Creek in the northern Gallatin Range released a small wind pocket from afar (photo). Given this recent avalanche activity and continued winds the avalanche danger is rated CONSIDERABLE on wind-loaded slopes and MODERATE on all others.
Bridger Range
Storms have neglected dropping snow in the Bridger Range over the last two days but made sure they got their fair share of winds. Avalanches are most likely to be triggered near the ridgelines where wind-loaded slopes could break and cornices are teetering. At low elevations on the west side of the range (Truman Gulch) a skier got pulse-raising collapses and cracks, the same as Alex on Saturday (video). An ice crust with facets below it are breaking 1-1.5 feet deep. This instability is very isolated, but anyone touring in that area should be cautious. For today, the avalanche danger is rated MODERATE on wind-loaded slopes and LOW on all others.
Eric 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.
Beacon Training Park at Beall: Open and free to the public for avalanche beacon practice seven days a week from 9 a.m. to 8 p.m., southeast corner of Beall Park in Bozeman (photo).
COOKE CITY
Next weekend, March 10 and 11, UYSC 21st Annual Hog Roast. More info here. Free avalanche rescue practice on Saturday.