GNFAC Avalanche Advisory for Thu Jan 28, 2010

The Madison Range, southern Gallatin Range and the Lionhead area near West Yellowstone:

Yesterday an observer in the southern Madison Range reported a large skier triggered avalanche that broke 8 inch diameter trees and was big enough to bury a car.  It fractured over most of the avalanche path on facets near the ground and occurred on an east aspect at an elevation of 7600 ft.  The scariest thing about this avalanche is that it was triggered from a 30 degree slope and propagated a fracture uphill to a 35 degree slope.

Through most of this season, the mountains near and between Big Sky and West Yellowstone have contained the weakest snowpack with faceted snow near the ground that should not be trusted.  Additionally some sheltered slopes contain a layer of surface hoar buried about 2 ft deep.  This layer is not widespread but has been found on isolated slopes on Lionhead, in the Taylor Fork, near Bacon Rind, near Buck Ridge, and in Beehive Basin.  Faceted snow, spotty surface hoar, and continued avalanche activity indicate dangerous avalanche conditions.  I would be especially cautious anywhere with a thin snowpack where it is easier to impact these facets while watching for surface hoar in areas sheltered from the wind.

For today, the avalanche danger on slopes steeper than 35 degrees is rated CONSIDERABLE.  On less steep slopes the danger is MODERATE.  Don't be fooled by this danger rating.  As happened yesterday, avalanches can be triggered from flatter terrain if it is connected to steeper slopes.

The Bridger and northern Gallatin Range, mountains around Cooke City and the Washburn Range:

A similar snowpack structure exists in the mountains near Bozeman and Cooke City, but it has gained some strength.  The problem is that each slope receives different meteorological inputs, and some slopes have stronger snow than others.  Skiers on Mt Ellis found stable conditions.  A regular observer near Cooke City has also found improving stability but has found some slopes that remain weak and even produced a couple of large collapses.  On Tuesday near Cooke City, my partner and I found similar conditions.  Even though faceted snow near the ground has gained some strength, it needs more time especially on slopes where the snowpack was previously thin.  Human triggered avalanches remain possible and the avalanche danger is rated MODERATE.

I will issue the next advisory tomorrow morning at 7:30 a.m. If you get out in the backcountry let us know what you find.  You can reach us at 587-6984 or email us at mtavalanche@gmail.com.

Monday, February 8: MONTANA ALE WORKS BENEFIT DINNER

Mark your calendars: Montana Ale Works is hosting a benefit dinner for the Friends of the Avalanche Center on Monday evening, February 8^th.  Chef Roth Jordan has assembled an amazing five course menu themed "Mountains of the World" with foods from Chile, Montana, France, New Zealand and Germany.  Dinner is limited to 40 seats with the first course served at 6:30 p.m.  Tickets to this event are $75, all inclusive, and available at Montana Ale Works.  More information is available on our calendar or by calling 587-7700.

8^th ANNUAL KING AND QUEEN OF THE RIDGE

The 8^th Annual King and Queen of the Ridge will be held at Bridger Bowl on Saturday, February 13^th.  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 62 classes reaching over 4,300 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 27 laps in 5 hours. 

2). Sponsor someone.  If you don't have someone to sponsor, consider sponsoring Mark, Eric or myself since we'll be hiking for dollars. 

You can go to http://www.bridgerbowl.com/events/view_event/15/  for more information and registration forms.

AVALANCHE EDUCATION CALENDAR

1. Big Sky

Moonlight Basin Avalanche Course: Join Moonlight Basin for a comprehensive, two-day and one evening avalanche awareness class.  Thursday, Jan 28^th 5-9:30 p.m. and Friday and Saturday, Jan 29 and 30, 8 a.m. to 4 p.m.  Contact: events@moonlightbasin.com or 406-993-6026

2. West Yellowstone, Holiday Inn

One-hour Avalanche Awareness Class - Saturday, January 30^th - 7 p.m. to 8 p.m.

3. Bozeman

Advanced Avalanche Workshop: The Friends of the Avalanche Center and ASMSU Outdoor Recreation are offering an Advanced Avalanche Workshop on the evenings of February 3 &4 with a field day on Saturday, February 6.  ADVANCED REGISTRATION IS REQUIRED.  For more information or to register contact friendsofgnfac@gmail.com