Archived Advisory for Mon Jan 14 2008

Monday, January 14th, 2008

Good morning. This is Scott Schmidt with the Gallatin National Forest Avalanche Advisory issued on Monday, January 14th, at 7:30 a.m. The Big Sky Snow Riders of Livingston, in cooperation with the Friends of the Avalanche Center, sponsor today’s advisory. This advisory does not apply to operating ski areas.

MOUNTAIN WEATHER

No new snow fell in our advisory area yesterday. Winds have been northwesterly at 5 – 15 mph in most mountains ranges. The exception, as always, is the Bridger range where ridge top winds have been 30 – 35 mph. Morning temperatures are in the mid-teens at 9000 feet.

Sunny skies and warm temperatures will be the order of the day. Winds will shift west, blowing 15 – 35 mph, and mountain temperatures will be in the upper 20’s at 9000 feet.

SNOWPACK AND AVALANCHE DISCUSSION

The Bridger Range:

The Bridger Bowl ski patrol didn’t released any significant avalanches on recently wind-loaded slopes yesterday. Wind slabs that developed over the past several days appear to be well bonded and are unlikely to produce human triggered avalanches. A group skiing in the northern Bridger Range yesterday reported finding isolated pockets of surface hoar on a slope with a northeast aspect. They did not find this crystal formation on any other slopes they investigated. This is the second report of buried surface hoar in this area so dig down and look hard at the snow stability before you commit to wind-loaded terrain in these mountains. Today, the avalanche danger in the Bridger range is MODERATE on all recently wind-loaded slopes. The avalanche danger on all non-wind-loaded slopes is LOW.

The northern Gallatin Range and northern Madison Range:

Doug and I rode into the Windy Pass area yesterday to look at the avalanche that buried a young man on Saturday. The avalanche occurred on a wind-loaded slope with a northerly aspect. It broke 2 – 4 feet deep, 150 feet wide, and ran about 800 vertical feet. The young man had climbed the chute several times before it avalanched. He was on his way down the hill after his last pass when the avalanche released and over-ran him. The avalanching snow hit the rider from behind and launched him and his sled toward a stand of trees. Seeing the danger of being strained through the trees the rider jumped from his sled, was tumbled several time, and came to rest buried under 2 – 3 feet of snow. His sled was carried thought the trees and came out the other side in several pieces. See pictures at

www.mtavalanche.com/photos/photos.php ).

The victim’s partner and three passing riders immediately started a beacon search and quickly located the buried man, who was unconscious but breathing. The young rider regained consciousness several minutes after being dug up, and after warming by a fire, was able to ride out on the back of his buddies sled.

The avalanche released on a layer of well developed facets sitting on a hard icy crust near the ground. This weak snow is buried under 2 – 4 feet of dense wind slab. See a video clip of the stability test at:

http://www.youtube.com/watch?v=EngZ4RQEyZQ&feature=PlayList&p=1ECB29D405CEF2C6&index=0

This weak layer/slab combination can be found on many slopes in the northern Madison and northern Gallatin Ranges. A group just outside of Big Sky yesterday remotely triggered an avalanche from 100 feet away as they skied a low angle slope. The fracture propagated into steeper wind-loaded terrain, releasing the avalanche in a thin snowpack near a rock band. See pictures at

www.mtavalanche.com/photos/photos.php

As with the avalanche near Windy Pass, this slide also ran on faceted snow near the ground.

Today, the avalanche danger in the northern Gallatin and northern Madison Ranges remains CONSIDERABLE on slopes steeper than 35 degrees that have been loaded by winds. A MODERATE danger exists on all other slopes.

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

There have been several reports of natural avalanche activity in the mountains around West Yellowstone this weekend. On Saturday, a group skiing in the Bacon Rind drainage reported a large natural avalanche on Ernie Miller Ridge, and a group riding in the Red Canyon area reported natural activity on steep wind-loaded slopes off Kirkwood Ridge. I was in the Lionhead area near West Yellowstone Saturday. My partner and I found the weak layer of faceted snow buried 1 – 3 feet beneath the surface is gaining strength. This layer still breaks cleanly during stability tests and is a concern on wind-loaded slopes, but we felt comfortable traveling on non-wind-loaded terrain. Today, for the southern Madison and southern Gallatin Ranges, the Lionhead area near West Yellowstone, the mountains around Cooke City, and the Washburn Range, a CONSIDERABLE avalanche danger exists on wind-loaded slopes steeper then 35 degrees. Wind-loaded slopes that are less steep, and all non-wind-loaded slopes, have a MODERATE danger.

LOST BACKPACK

I left a blue backpack sitting in the parking area at the top of Targee Pass on Saturday, January 12th. If any of you folk happened to have picked it up would you please call at the Avalanche Center at 406-587-6984. I’d really appreciate it.

AVALANCHE EDUCATION

The Friends of the Avalanche Center will present a one hour avalanche awareness lecture on Tuesday, January 15, 2008 at the Bozeman Public Library. This presentation starts at 7:00 p.m. and is sponsored by the Montana Outdoor Science School. Contact them at 406-582-0526 for more information.

The Friends of the Avalanche Center will present a one hour avalanche awareness lecture for snowmobilers on Wednesday, January 16, 2008 at Redline Sports, 2050 Harrison Ave., Butte, MT. This presentation starts at 6:00 p.m. Contact Redline Sports at 406-782-9129 for more information.

The Friends of the Avalanche Center will present a one hour avalanche awareness lecture for snowmobilers on Wednesday, January 16, 2008 at the Billings Public Library. This presentation starts at 7:00 p.m. and is sponsored by Yellowstone Polaris. Contact them at 406-259-7777 for more information.

The Gallatin National Forest Avalanche Center will present a 2 day avalanche awareness seminar for snowmobilers on Saturday and Sunday, January 19-20, 2008. Saturday’s session will be held at Pond’s Lodge from noon to 4:30 p.m. Sunday’s field session will be from 9:00 a.m. to 3:00 p.m. Information about Sunday’s session will be given during Saturday’s classroom session. Contact the Avalanche Center at 587-6984 for more information.

Angela Patnode will present a free 1-hour Avalanche Awareness Class for women at 7:00pm at the Bozeman Public Library in the small conference room on Tuesday, January 29th. This class is sponsored by Bozeman-based Team WinS (Women in Sports). For more information visit www.teamwins.org.

I’ll issue the next advisory tomorrow morning at 7:30 a.m. If you get out in the backcountry give us a call or email with your observations. You can reach us at 587-6984 or email us at mtavalanche@gmail.com .