Good Morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Wednesday, March 1st at 6:45 a.m. Today’s advisory is sponsored by Wisetail and Montana State Parks. This advisory does not apply to operating ski areas.
In the last 24 hours 1-2” of snow fell in most mountain locations with 3” outside Cooke City. Winds are steady from the west at 15-20 mph with gusts of 40 mph last night. Under partly cloudy skies temperatures are in the low single digits. Today has increasing clouds, temperatures in the teens and snow showers starting later this afternoon. By morning there will be 1-2” around West Yellowstone and 3-4” near Cooke City.
Bridger Range
Yesterday, Eric and I went to Saddle Peak to check on stability. This area had feet of snow from the weekend (4-6’ of powder snow measuring 1.5” of snow water equivalent) and winds. We anticipated finding wind slabs, but did not. Instead we found mostly stable conditions (video). The weekend’s snow bonded well to the old surface, did not weigh much and fell onto a snowpack without prominent weak layers. We went hunting for wind slabs and came up empty, but other areas may have them. If winds increase and move snow today, the danger will rise too. For today, the avalanche danger is MODERATE on slopes with a wind-load and LOW on all others.
Madison Range Gallatin Range Lionhead area near West Yellowstone
Yesterday’s 1-2” of new snow will not adversely affect the snow stability in the mountains from Bozeman to West Yellowstone. There is one weak layer to be concerned with, a thin strip of facets buried 1.5-3’ under the surface. In the southern ranges these grains are sitting on a thin ice crust and break clean in stability tests. A week ago they avalanched at Lionhead after a large snowstorm. With time this layer is getting stronger, but a few slopes remain unstable. Alex had this layer propagate in an Extended Column Test at Bacon Rind last Friday and steered clear of a steeper slope. Without obvious signs of instability, the only reliable way to determine stability is to dig and test, #justlikeAlex. Since avalanches are possible, the danger is rated MODERATE on all slopes.
Cooke City
The mountains around Cooke City have gotten 3” of snow every day for the last three days. The snowpack is deep, strong and lacks a worrisome weak layer. New snow coupled with wind creates wind slabs, our main avalanche concern. Beware of wind drifts near ridgelines and in gullies from cross-loading. Cracking of small drifts is a sign that bigger, thicker ones could be triggered. 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.
Note: Cornices have grown with recent snow and wind. These monsters hang far off ridgelines and can be easily broken free by simply skiing nearby. Give them a wide berth. Many skiers and climbers have been injured or killed when a cornice breaks underfoot.
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
Weekly rescue training and snowpack update, 6:30-7:30 p.m., Soda Butte Lodge on Friday, Lulu Pass Road for field location Saturday (Look for the yellow sign).
Bozeman
TONIGHT, March 1, 1-hr Avalanche Awareness, 6-7p.m., REI Bozeman.
March 4, Pinhead Classic, Proceeds to benefit Friends of GNFAC. More info here.