Good morning. This is Eric Knoff with the Gallatin National Forest Avalanche Advisory issued on Monday, February 27 at 7:30 a.m. Alpine Orthopedics and Lone Peak Brewery, in partnership with the Friends of the Avalanche Center, sponsor today’s advisory. This advisory does not apply to operating ski areas.
Since yesterday morning a trace to one inch of snow fell in most areas with the exception of the Bridger Range which picked up an additional 3-5 inches between 7 am and noon yesterday. Winds have been decreasing over the past 24 hours and are currently blowing 5-15 mph out of the SSE. Temperatures are in the single digits under mostly cloudy skies. Today, temperatures will warm into the low twenties F and winds will gradually shift to the SW blowing 5-15 mph. Skies will be partly cloudy in the north, but a weak weather disturbance in the south will produce a chance of snow showers for the mountains around West Yellowstone and Cooke City, 1-2 inches is possible by this afternoon. An unsettled weather pattern will remain over the southern mountains through tomorrow, but the north will stay mostly dry.
The Bridger Range, the Madison and Gallatin Ranges, the Lionhead area near West Yellowstone and the mountains around Cooke City:
Saturday's storm definitely packed a punch. By the time it was all over the Bridger Range picked up over a foot of snow and the mountains around West Yellowstone picked up 8-10 inches. All other areas picked up 6-8 inches. Winds were also strong during the storm blowing 30-40 mph out of the WNW. Regardless of the amounts, this latest blast of snow added additional stress to an already burdened and irritated snowpack.
Yesterday, multiple natural and human triggered avalanches were reported throughout our advisory area. The most notable was a large natural avalanche that occurred on Saddle Peak just south of Bridger Bowl (photo, photo). This slide broke 3-5 feet deep on facets near the ground and propagated hundreds of feet across. Fortunately nobody was involved. Additional activity includes:
- A skier triggered slide yesterday on a south facing slope near Bradley Meadow north of Bridger Bowl. The slide initiated in the new snow but stepped down to the ground.
- A remote trigger yesterday on an east facing slope near Big Sky. The same skier also experienced widespread cracking and collapsing.
- On Saturday a skier near Cooke City experienced cracking and collapsing on lower elevation south facing slopes.
- Also on Saturday, skiers near West Yellowstone experienced widespread cracking and collapsing and received unstable results during stability tests (video).
- On Friday a skier triggered and was caught in a large slide on Saddle Peak south of Bridger Bowl (photo). The following day a skier triggered a large side in Wolverine north of Bridger Bowl (photo, video).
Unfortunately there are very few slopes that lack buried persistent weak layers. A layer of weak, near surface facets buried 1-3 feet deep can be found on most aspects and elevations. Avalanches initiated on this layer can easily step down to facets near the ground.
Although natural activity will likely subside today, there is little question the snowpack will remain touchy to the weight of a skier or rider. Traveling in avalanche terrain will be like racing the Indy 500 without wearing your seat belt – you might get away with it, but the slightest mistake could be tragic.
Today, very dangerous avalanche conditions exist on slopes steeper than 35 degrees which have a HIGH avalanche danger. Slopes less than 35 degrees have a CONSIDERABLE avalanche danger.
Doug 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.
Additional Information
The accident reports for the avalanche fatality near Cooke City and the slide on Saddle Peak are now available. See links below.
http://www.mtavalanche.com/sites/default/files/Saddle%20Peak%20Accident_Public.pdf
http://www.mtavalanche.com/sites/default/files/Daisy%20Pass%20Avalanche%20Public.pdf
Also, another avalanche fatality occurred on Saturday near Marias Pass outside of Glacier National Park. This makes the third avalanche fatality to hit Montana in the past week and raises the total number of avalanche fatalities in the United States to 21.
Events/Education
FREE 1-hr Avalanche Awareness Lecture, Friday, March 2, 7-8 p.m. at the West Yellowstone Holiday Inn in the room next to the bar.
Come to Bridger Bowl on Saturday, March 17th (St. Patrick’s Day) with telemark skis, AT skis, alpine skis, snowboards, split boards, or even snow blades. The theme is Snowpocalypse based on the wildly popular Mayan 2012 apocalypse. $30 gets you into the races, a pint glass, t-shirt, a good time, a raffle ticket, and food by Cafe Fresco. Pre-register at Mystery Ranch or Grizzly Ridge March 11-16. Visit http://pinheadclassic.com/ or the Pinhead Facebook page for more info.