GNFAC Avalanche Advisory for Fri Nov 6, 2015

Not the Current Forecast

Good Morning. This is Doug Chabot with early season snowpack information issued at 7:30 a.m. on Friday, November 6. Today’s information is sponsored by Mystery Ranch in partnership with the Friends of the Avalanche Center. This information will be updated as weather and snow conditions change.

AVALANCHE INCIDENT

Yesterday, two hunters hiking up Sacajawea Bowl in the northern Bridger Range triggered an avalanche at 6:50 a.m. The slide broke 20 feet above them, was 40-50 feet wide and carried them 400 vertical feet to the bottom (photo). One of the men was unconscious but came to. After a self-evacuation and visit to the emergency room they were released with no critical injuries. Our report on the incident is located here.

Mountain Weather

At 5:30 a.m. light snow flurries are still falling but will end soon. Overnight the mountains picked up 2-4 inches of snow with west to northwest winds blowing 15-20 mph. Currently, temperatures are in the mid-teens. Today will turn sunny with westerly winds blowing 20 mph. The weekend will be dry and sunny with daytime temperatures reaching the upper thirties. Our next snow storm will roll into our area late Monday. Let’s keep our fingers crossed for more El Nino action.

Snowpack and Avalanche Discussion

The snowpack doesn’t care about our mode of travel: foot, skis, snowmobile, or snowshoe. As the two hunters experienced, under unstable conditions it’s possible to trigger an avalanche, even during early season. New snow and strong winds over the last five days have created drifts of snow near the ridgelines and filled up gullies. These locations harbor thicker pillows of wind slab and are our main avalanche concern. Unfortunately, these slopes are where we want to ski to avoid rocks…a double-edged sword.

Two parties of skiers reported good, stable conditions above 9,000 feet in Beehive Basin near Big Sky with a challenging exit to the car because of thin snow (photo). Winds loaded slopes from the Bridger Range to West Yellowstone and Cooke City and wind-loaded slopes should be approached carefully and avoided completely if they show instability in tests, crack or collapse on approach, or if there are any nearby slides.

Most hunters travel solo and do not carry rescue gear, so I recommend they avoid open, steep, snow-covered slopes. Ice climbers spend a lot of time approaching and descending wind-loaded gullies, currently a risky proposition. Climbs like the north-face of the Sphinx are very serious endeavors; two climbers died in an avalanche on the approach in 2004 in conditions similar to now. Carry rescue gear, practice with it, go with a partner and only expose one person at a time to avalanche terrain. Eric made a video last week on getting our avalanche gear ready, a timely reminder.

We are not issuing danger ratings until we begin daily avalanche forecasts, which is dependent on snowfall. In the meantime, we will update this information as conditions change. We need your observations, so please drop us a line if you get out: mtavalanche@gmail.com.

AVALANCHE EDUCATION

A complete calendar of classes can be found HERE.

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

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 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

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