AVALANCHE INCIDENT
November 5, 2015 - Sacajawea Bowl
Around 6:50am on Thursday November 5th, two hunters were walking up and over the saddle North of Sacajawea peak. They were on the shoulder of the peak to the North (often referred to as Hardscrabble) when they triggered an avalanche that broke 20 feet above them and was 40-50 feet wide. They were carried 300 feet over a series of rocks and cliffs. One Hunter was injured and went to the ER. He was released and cleared of critical injuries. We will update our website with new information in the next few days.
This is Alex Marienthal with early season snowpack information issued at noon on Wednesday, November 4. Today’s information is sponsored by Grizzly Outfitters in partnership with the Friends of the Avalanche Center. This information will be updated as conditions change.
Winter is here. Since Monday night, the mountains from Bozeman to West Yellowstone received around 1.2 inches of snow water equivalent (SWE), giving us a snow depth up to 18 inches. Since Sunday, the mountains around Cooke City received 2.6 inches of SWE, bringing their snow depth to 26 inches. Southerly winds during the storm were moderate with gusts of 40 mph. The exception is the Bridger Range where winds were light and easterly. Temperatures this morning were in the high teens F in most mountain locations.
Winds over the next few days will be out of the west to northwest at 20 to 35 mph. Another 2-4 inches of snow is expected in the mountains around Bozeman and Big Sky Thursday night, with slightly larger amounts near Cooke City. This weekend will be dry with our next chance for precipitation early next week. Mountain temperatures over the next few days will be in the 20s F and reach the upper 30s F by Sunday.
The mountains in our area have 18 to 26 inches of snow on the ground. This last storm delivered 12 to 18 inches of dense snow with moderate winds. Avalanches are possible where there is enough snow to ski, and where the wind has loaded slopes and created deeper slabs of snow. Deeper areas will be more appealing for skiing and riding, but will also have a higher potential to avalanche. Wind direction varied through the storm, so look for these wind slabs near ridgetops and in gullies on all aspects. Over the weekend, skiers found wind slabs on Sacajawea peak in the northern Bridger Range (photos). Expect to find wind slabs over the next few days and into the weekend.
We almost always hear of unintentionally triggered avalanches this time of year. Besides getting buried, getting caught in a slide can have large consequences due to many exposed hazards like rocks and logs. Three years ago, three skiers were caught, partially buried, and injured near Sacajawea peak. Our current weather and snow conditions are similar to those that contributed to that incident (incident report).
Climbers need to be cautious of avalanches as well. In 2004, two ice climbers were caught and killed in a small slide on the Sphinx that swept them over large cliffs. Small avalanches above steep terrain can have large consequences. Hunters should also be aware of avalanches. Hunters often travel solo, through drainages and gullies, and are not thinking about the snow. A small avalanche in a confined gully can deeply bury a person due to snow piling up deep. These dangers are not hypothetical. Hunters and ice climbers have died in avalanches in southwest Montana.
If you get out in the mountains to ski, climb, or hunt watch out for steep open slopes, especially where the wind has deposited thick slabs of snow. Travel one at a time into avalanche terrain and watch one another. If you are out searching for turns you should always carry and know how to use avalanche rescue gear. This includes a transceiver, shovel, probe, and a partner that has the same. Don’t cut corners because it’s early season. Travel protocol in avalanche terrain is the same no matter what you are doing. The snow doesn’t care if you’re carrying a rifle, ice tools, or wearing skis.
We will update this information as conditions change. In the meantime, tune-up your avalanche knowledge and get your gear in order. Check out Eric’s video on Pre-Season Gear Preparation. Take a look at our Education Calendar for a current list of offerings.
Upcoming Classes:
November 11, 8:30 a.m. to 7:30 p.m., Bozeman, Montana State University, MSU Snow and Avalanche Workshop: http://www.montana.edu/snowscience/workshop/index.html
November 17, 6 p.m.: Billings, Avalanche Awareness at Basecamp.
November 18, 6 p.m.: Bozeman, Avalanche Awareness at MSU Roskie Hall
November 18, 7 p.m.: Big Sky, Avalanche Awareness at Grizzly Outfitters.
November 19, 7 p.m.: Big Timber, Avalanche Awareness at Sweet Grass County High School
MSU - Introduction to Avalanches with Field Course
The workshops are held on Wednesday and Thursday evenings, with a field course on Saturday. Different topics are presented each evening. Topics include: avalanche terrain recognition, the affect weather has on avalanche hazard, the development of the mountain snowpack, decision making skills, and basic search and rescue procedures.
December 2, 3 and 5 or 6, 2015: https://www.ticketriver.com/event/16858
West Yellowstone: Snowmobiler Introduction to Avalanches with Field Course
Five hours of lectures are followed by a full day field course. Topics covered include: avalanche terrain recognition, the affect weather has on avalanche hazard, the development of the mountain snowpack, decision making skills, and basic search and rescue procedures.
December 17 and 18, 2015: https://www.ticketriver.com/event/17356