GNFAC Avalanche Advisory for Tue Feb 2, 2010

Not the Current Advisory

Good Morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Tuesday, February 2, at 7:30 a.m.  Montana Ale Works, in cooperation with the Friends of the Avalanche Center, sponsor today's advisory.  This advisory does not apply to operating ski areas.

Mountain Weather

Only remnant flurries fell after yesterday's early morning storm.  Temperatures reached the 20s and ridgetop winds blew 15-20 mph from the west-southwest.  Today will be mostly cloudy with mountain temperatures again reaching the mid 20s before dropping to the low teens tonight.  Ridgetop winds will continue to be west-southwest at 15-20 mph. A few bands of moisture may drop a dusting of snow, but it won't be enough to really care about.

Snowpack and Avalanche Discussion

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

It's always better to be the hunter than the hunted.  On Monday Eric and I went hunting for instability and we found it.  We skied and dug pits in the southern Madison Range near Hebgen Lake and got clean shears on a buried surface hoar layer two feet down (video). This layer is visible as a stripe in the snowpit wall.  Our tests also fractured on the large sugary grains near the ground, so pick your poison.  Both these layers were the reason we skied low angled terrain.  A snowmobiler on Sunday triggered a slide on one of these layers only a couple miles to the south of us. Last Thursday a snowmobiler triggered a small slide in Carrot Basin a few miles to the north.  This activity, plus our poor stability tests indicate a persistent problem. 

The 5-7 inches of new snow that fell in the wee hours Monday morning improved the riding and skiing without spiking the avalanche danger.  All the ski patrols in the Lone Mountain vicinity got easy ski cuts on wind-loaded slopes.  In the last 24 hours winds have been light and the new snow seems to have bonded well to the old surface.  Our main avalanche concern continues to be the buried faceted snow near the ground and/or the surface hoar which is found in the southern ranges. Given these conditions, the avalanche danger is rated CONSIDERABLE on all slopes steeper than 35 degrees.  Less steep slopes will have a MODERATE danger. 

Be aggressive in your search for instability.  Don't become the hunted.

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

In the Bridger Range 8-10 inches of denser, 7.5% snow skied well and stayed put.  Other than easy ski cuts on some wind-loaded slopes near the ridgelines, the new snow did not avalanche yesterday.  The snowpack in the northern mountains still has lingering instabilities on weak, faceted snow near the ground.  A snowmobiler on Thursday triggered a slide north of Ross Pass on this layer, but overall these slopes are becoming harder to find. A skier touring far and wide in Hyalite on Sunday found these facets on a few slopes and was conscious of being "lulled by a supportable slab and enticing skiing conditions."  Snow Rangers in Cooke City found 5-6 inches of light, dry snow yesterday.  They dug a snowpit below Mount Abundance, very near a pit they dug on Jan 20.  Besides a deeper snowpack, their stability tests showed good strengthening --easy fractures 12 days prior were not breaking.  But let's not forget that faceted snow near the ground which formed at the beginning of December still avalanched as recently as five days ago.  Strengthening is a slow, tedious process.  For today, the avalanche danger is rated MODERATE on all slopes.

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


Mark your calendars: Montana Ale Works is hosting a benefit dinner for the Friends of the Avalanche Center on Monday evening, February 8th.  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.


The 8th Annual King and Queen of the Ridge will be held at Bridger Bowl on Saturday, February 13th.  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 Doug since we'll be hiking for dollars. 

You can go to  for more information and registration forms.


1. 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:


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