GNFAC Avalanche Forecast for Fri Jan 28, 2011

Not the Current Forecast

Good morning. This is Mark Staples with the Gallatin National Forest Avalanche Advisory issued on Friday, January 28, at 7:30 a.m. The Big Sky Ski Patrol, in cooperation with the Friends of the Avalanche Center, sponsors today’s advisory. This advisory does not apply to operating ski areas.

Mountain Weather

This morning temperatures were in the high 20s F with winds blowing 10-30 mph from the W. Near Cooke City and West Yellowstone temperatures were in the high teens F with winds blowing 5-15 mph. Similar conditions will continue today with high temperatures in the low to mid 30s F while high temperatures near Cooke City and West Yellowstone will reach the low 20s F, and winds shouldn’t change much. A few snowflakes may fall tomorrow morning but no accumulations are expected. Colder air should begin arriving this evening and produce a cooling trend through the weekend.

Snowpack and Avalanche Discussion

The Bridger, Madison and Gallatin Ranges, the Lionhead area near West Yellowstone, and the mountains around Cooke City and the Washburn Range:

Yesterday a sizeable avalanche (photo) was observed on Hardscrabble Peak in the northern Bridger Range near Fairy Lake. It was triggered by a falling cornice and occurred near another avalanche that happened last weekend. While many slopes have a strong and stable snowpack, some do not as illustrated by this avalanche. Yesterday, my partner and I skied in the Lone Lake Cirque, backcountry terrain on the north side of Lone Mountain at Big Sky. We found shallow, weak areas and deep, strong areas in the snowpack, but there is a difference between weak and unstable. We felt comfortable skiing this terrain because many of the shallow, weak areas had been scoured by strong winds thus removing the load of recent snow. We also found a few thin wind slabs which broke under our skis and didn’t propagate or run downhill more than a few feet. On southerly aspects these thin wind slabs are more sensitive having some faceted crystals under them. In other areas a similar layer exists about 12-16 inches deep at an interface between old snow and newer snow.

Last week avalanche activity spiked as new snow accumulated and added stress to the snowpack. Overall we have a stable snowpack this year, and avalanche activity quickly subsided once snowfall ended. A few issues linger on specific terrain features making human triggered avalanches possible. A good example of how to select stable slopes occurred on Wednesday in Hyalite Canyon. A group of skiers wanting to ski into a specific basin found a thin snowpack (example photo) on their chosen line. They quickly changed plans, found a slope with a deep snowpack and enjoyed a good day of skiing in a slightly different area with stable snow. For today the avalanche danger is rated MODERATE on all slopes steeper than 35 degrees. All other slopes have a LOW avalanche danger.

Side note: Stability assessments in backcountry areas like Saddle Peak and the Lone Lake Cirque are very difficult. These areas combine easy access with high consequence terrain where even a small avalanche can be deadly. Yesterday I asked many experienced avalanche professionals for advice on where and how to assess stability in the Lone Lake Cirque, and no one gave me a easy “cookie cutter” approach. The point is to be aware of this difficulty, take these areas seriously and focus on bull’s eye information like recent avalanche activity, recent snowfall, or recent wind-blown snow. Remember that some information like seeing ski tracks on a slope is not bull’s eye information and should not be considered equally.

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.

TODAY: Beacon Park Opening Celebration

The Bozeman Recreation Department is celebrating the opening of the Bozeman Beacon Park on Friday, January 28th from 4:00 to 6:00 p.m. at Beall Park, 415 N. Bozeman. The Recreation Department will offer food, refreshments, music, and training on how to use the park with your avalanche beacon. This event is free to the public. For information call 582-2290.

West Yellowstone: Beacon Park Operational

Skiing or riding near West Yellowstone? Test your beacon skills at a beacon park near the old airport where you can search for pre-placed beacons switched on/off by a control panel. Look for it by orange snow fence and signage just south of the snow cross track.

9th ANNUAL KING AND QUEEN OF THE RIDGE

The 9th Annual King and Queen of the Ridge will be held at Bridger Bowl on Saturday, February 12.  ALL proceeds go to the Friends of the Avalanche Center who use the money to promote avalanche education in southwest Montana.  Last winter we taught 64 classes reaching over 4,900 people.  You can help raise money to continue this education in 2 ways:
1). Get pledges and hike the ridge.  You don’t have to do 20 laps – you can get flat pledges and hike just once!  Or you can test your mettle and try and break John Yarington’s record of 29 laps in 5 hours.  
2). Sponsor someone.  If you don’t have someone to sponsor, consider sponsoring the GNFAC since we’ll be hiking for dollars.  
Go to http://bridgerbowl.com/events/view_event/81/ for more information and registration forms.

Avalanche Education

February 2, 3, and 5 in Bozeman

Advanced Avalanche Awareness –Wednesday & Thursday 7:00p.m. – 9:30 p.m. at MSU SUB Room 235 with a field day on Saturday at Bridger Bowl. ADVANCED REGISTRATION REQUIRED (more information) (Register)

February 12 and 13 in Cooke City

Avalanche Workshop for Snowmobilers – Lectures on Saturday 12 p.m. – 4:30 p.m. and a field session on Sunday 9 a.m. – 3 p.m. ADVANCED REGISTRATION REQUIRED (more information and registration)

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