Good Morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Wednesday, February 26 at 7:30 a.m. Javaman and the Pinhead Classic Telemark Festival sponsor today’s advisory. This advisory does not apply to operating ski areas.
Under clear skies mountain temperatures are in the mid-teens and ridgetop winds are light at 15-20 mph from the west. High pressure will allow for sunny skies and temperatures reaching the upper 20s as winds remain light. Skies will cloud up tonight and snow is forecasted for Thursday, but for today, lather on the sunscreen and enjoy the bright sunshine.
Cooke City
Yesterday morning snowfall tapered off in the mountains around Cooke City and the snowpack finally got a reprieve from loading. Over 10” of snow water fell in February, which is the equivalent of ten feet of snow. Constant loading means constant stress and even strong snowpacks need a rest now and again. The primary avalanche concern in Cooke City is steep wind-loaded slopes. Although conditions have calmed in the last 24 hours, winds were strong and loading was heavy during the two days prior. Lower-angled terrain will have safer riding while steep wind-loaded slopes could still avalanche. If you see recent avalanche activity stay off of slopes that have a similar aspect and elevation. For today, wind-loaded slopes steeper than 35 degrees have a CONSIDERABLE danger and all others are rated MODERATE.
The Bridger Range Northern Gallatin Range
Northern Madison Range
Avalanche conditions have been quiet in the northern mountains. Even with all the new snow and wind since Thursday (over 2” of water weight), there has been relatively little activity reported. The primary avalanche concern is near the ridgelines where wind drifts are lurking. In the northern Madison and northern Gallatin Ranges an additional concern is a layer of facets buried 2-3 feet deep that avalanched and buried two skiers in Beehive Basin eight days ago. It has gained a lot of strength since then and is harder to trigger, but we cannot forget about it. Big Sky Snow Safety aptly wrote, “Enjoy the powder, but keep focused on the snowpack.” Eric explains this situation in a video he made on Sunday during a tour up Hyalite. For today, given wind-loads and a buried weak layer, the avalanche danger is rated MODERATE on all slopes.
Southern Madison Range Southern Gallatin Range
Lionhead area near West Yellowstone
The southern mountains have us scratching our heads a bit. What we are finding is not lining up with what we think should be happening. First, the weak layer of facets buried two feet deep is strengthening very quickly, much more so than we anticipated. I could not get this layer to break above Hebgen Lake yesterday (photo), yet across the valley near Quake Lake slopes naturally avalanched on this layer eight days ago. Mark also found this layer strengthening in Cabin Creek on Saturday and also around Lionhead yesterday. Second, and even more vexing, is that Mark found three avalanches at Lionhead that broke on facets on the ground (video, four photos). These facets formed in early December and we have not seen activity on this layer since mid-January. These likely avalanched in the last few days when loading was minimal. Sometimes we just don’t know the trigger or root cause, but what we do know is this: avalanches just broke at the ground and someone may trigger the next. Slopes could avalanche bigger and deeper than one may think and riders should consider where they park carefully. There’s no reason to be exposed in the runout zone. For today, the avalanche danger is rated MODERATE on all slopes.
I 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
BOZEMAN, Thursday, March 6, 6:30-8:00 p.m.; REI, 1-hour Avalanche Awareness Lecture.
Our complete calendar of events can be found HERE.