GNFAC Avalanche Advisory for Wed Jan 20, 2016

Not the Current Forecast

Good morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Wednesday, January 20, at 6:30 AM. Today’s advisory is in memory of Tyler Stetson. Tyler was killed in an avalanche in Beehive Basin on this day eight years ago. This advisory does not apply to operating ski areas.


AVALANCHE FATALITY

Yesterday afternoon a skier was killed in an avalanche near Cedar Basin in the northern Madison Range. The avalanche took him into trees and his three partners rescued him quickly, but he died of trauma. I am withholding some information until families are fully notified.  I will investigate the scene today and write a report later in the week. We are extremely sad to hear of this incident and our condolences go out to his family and friends.


Mountain Weather

At 6 a.m. the mountains received 4 inches in the northern ranges and 6 inches in the south. It is still snowing and will drop another 4-6 inches by the time the storm shuts down later this afternoon.  Winds have increased and are averaging 20-30 mph out of the west to southwest with gusts of 40 mph and will remain strong today.  Mountain temperatures are near 20F and won’t warm much.


Snowpack and Avalanche Discussion

Bridger Range   Madison Range   Gallatin Range  

Lionhead area near West Yellowstone   Cooke City

Yesterday, a skier died in an avalanche. I was told it was in an area that was wind-loaded and that the slope was not very big. Also yesterday, skiers in Frazier Basin in the Bridger Range triggered a large slide but were not caught, also in terrain that was wind-loaded (photo1, photo2). The Frazier Basin party saw natural avalanches at the ridgeline earlier in the day, a sign of instability, and confessed to “pushing it”. A snowmobile guide in Cabin Creek of the southern Madison Range noted a couple small natural avalanches too (photo3). The snow that fell over the last few days is avalanching. It is either breaking on a density change in the storm snow or on a weak layer of small-grained facets a foot or two under the surface. These small facets have been seen everywhere except in Cooke City. Eric was in the Bridger Range on Monday and made a great video explaining what to look out for in the snowpack.

Alex toured into terrain above Hebgen Lake and also found a snowpack with facets near the surface and depth hoar at the ground (video). The depth hoar is getting stronger, but not to be trusted. I was in Cooke City Sunday and Monday and made a video showing the thick, dense slab perched on the weak facets that still scare me.

Already this morning .3-.4 inches of snow water equivalency fell and this will easily double with today’s storm. The upper weak layer in the snowpack started avalanching yesterday before this storm. It does not take a science degree to deduce that today will be worse. Throughout our advisory area the avalanche danger is rated HIGH on slopes that are wind-loaded since natural avalanches are likely. On slopes without a wind-load the danger is rated CONSIDERABLE.


Alex will issue the next advisory tomorrow morning by 7:30 a.m. If you have any snowpack or avalanche observations to share, drop us a line at mtavalanche@gmail.com or leave a message at 587-6984.


BEACON PARK

The Friends of the Avalanche Center and Bozeman Parks and Rec installed a Beacon Park at Beal Park.  It is a great way to practice single and multiple burials.  It is available 9 a.m. -4 p.m., M-F.


EVENTS and AVALANCHE EDUCATION

A complete calendar of classes can be found HERE.

TONIGHT: ASMSU Intro to Avalanches w/ Field Course

January 20, 21 and 23 or 24: https://www.ticketriver.com/event/16861

The workshops will be held on Wednesday and Thursday evenings, with a field course on either Saturday or Sunday. Different topics will be presented each evening. Topics include: avalanche terrain recognition, the effect weather has on avalanche hazard, the development of the mountain snowpack, decision making skills, and basic search and rescue procedures.

Dillon: January 23 and 24, Intro to Avalanches w/ Field Course, https://www.ticketriver.com/event/18441

West Yellowstone: Saturday, January 23, and 30, 1hr Avalanche Awareness, West Yellowstone Holiday Inn, 7-8:30 p.m.

Advanced Avalanche Workshop w/ Field Course

January 27, 28, and 30: https://www.ticketriver.com/event/16862

Course content includes: snowpack metamorphism, the mechanics of avalanche failure and fracture, and decision-making. Different topics are covered each evening session. The field session includes snowpack analysis and avalanche rescue scenarios.

Cooke City: Saturday, January 30, Companion Rescue Clinic for Snowmobilers.  Information and registration here: https://www.ticketriver.com/event/18078

Lewistown: Saturday, January 30, 9:00 a.m., 1hr Avalanche Awareness for Snowmobilers, Lewiston Honda-Polaris.  More info HERE.

EVENT at BRIDGER BOWL: February 6, King and Queen of the Ridge. A day of hiking and skiing the Ridge as a fundraiser for the Friends of the Avalanche Center.  Teams and individuals are welcome! More info here: http://bridgerbowl.com/event/king-and-queen-of-the-ridge