GNFAC Avalanche Advisory for Wed Jan 27, 2010

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

A snowboarder triggered a soft slab avalanche on an ENE facing slope in the northern Madison Range yesterday, but luckily no one was caught.  Fourteen inches of new snow on a sun crust avalanched 150 feet wide and ran 1,000 feet vertical.  He wrote that the slope was only 33 degrees steep and that it also slid 2 weeks ago.  Besides this new snow avalanching, we're still concerned with a few deeper layers.  Sugary, faceted snow is still at the ground on most aspects and elevations.  Like a fine wine it's becoming mellower with age, but it can still avalanche.  On some slopes there's a layer of feathery surface hoar that's buried two feet down.  The fact that it's on only some slopes makes it tricky to find.  The problem is that it's breaking clean and easily.  On Sunday I collapsed this layer with a large "whumph" as I skied.  The surface hoar failed, and like dominoes tipping over the fractures propagated 200 feet away creating a four inch crack on a small hill.  I was able to jump on this fracture about ten minutes later and trigger a small avalanche. I love doing that.

Collapsing, cracking and a human triggered avalanche yesterday are reminders that the snowpack is still weak and unstable. For today, the avalanche danger on slopes steeper than 35 degrees is rated CONSIDERABLE.  On less steep slopes the danger is MODERATE, but don't let this rating fool you.  In these conditions avalanches are still possible and can even be triggered from flatter terrain.

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

Mark and his partner did a one day blast to Cooke City yesterday.  They rode around, dug pits and got a good sense of the snow stability, which has improved greatly in the last few weeks.  With five feet of snow on the ground these mountains have the deepest snowpack in our area.  Large grains of facets near the ground are our greatest concern, but these are getting stronger. We are no longer describing these facets as "playing in a sandbox" when we dig snowpits. Mark assessed that an unlucky person could still trigger a slide since there's spotty instabilities.

The snowpack in the mountains around Bozeman is 3-4 feet deep and has enough weak facets near the ground to warrant caution.  The recent load of snow over the weekend (1" SWE) combined with untrustworthy facets underlying the snowpack point to a MODERATE avalanche danger on all slopes.

Mark 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 8th.   Menu and pricing details are coming soon.  Last year's special five course meal was an enormous hit and raised $2,300!

8th ANNUAL KING AND QUEEN OF THE RIDGE

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 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. Billings- TONIGHT

Avalanche Awareness and Rescue Class- 6 to 9 p.m. at Beartooth Harley. 

2. Bozeman-TONIGHT

BASIC AVALANCHE WORKSHOP:  The Friends of the Avalanche Center and ASMSU Outdoor Rec are offering a Basic Avalanche Awareness Class the evenings Wed, Thur, 27 & 28 January with a field day on Saturday, 30 January. $25 donation. No sign up required. http://www.mtavalanche.com/education/classes/basic

3. Big Sky

Moonlight Basin Avalanche Course: Join Moonlight Basin for a comprehensive, two-day and one evening avalanche awareness class.  Thursday, Jan 28th 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

4. West Yellowstone, Holiday Inn

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