This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Tuesday, January 3 at 7:30 a.m. This advisory is sponsored by Mystery Ranch in partnership with the Friends of the Avalanche Center. This advisory does not apply to operating ski areas.
Yesterday was sunny and unseasonably warm with high temperatures in the Bridger Range reaching 45F. Other mountain areas had temperatures in the high 20s to low thirties. Winds blew hard out of the west to southwest with gusts hitting the 50s, but have lessened overnight and will die down even further this afternoon. Today will be more of the same: sunny and mild. This pattern of high pressure looks to stay with us through Thursday.
The Bridger, Madison and Gallatin Ranges, the Lionhead area near West Yellowstone and the mountains around Cooke City:
The avalanche danger spiked on Saturday immediately after the storm. In two separate incidents a skier and snowmobiler were killed in avalanches near Cooke City. Further to the west, far outside our forecast area, a snowmobiler on Sunday was also killed in an avalanche east of Phillipsburg. With no new snow and minimal wind-loading, the snowpack is starting to stabilize as it adjusts to the new load. However, this is when stability assessment starts to get tricky. Avalanche activity and other obvious signs of instability are decreasing. Not all slopes are unstable, but a lot are. I’m more worried about human triggered slides this week than I was over the weekend. My advice is simple: Be conservative.
Yesterday Karl and I, plus two locals, investigated the avalanche that killed a backcountry skier on Saturday. The avalanche was triggered south of Cooke City up Hayden Creek. The slide was approx 800 feet wide, 250 feet vertical with a crown depth averaging 1-3 feet deep and 35 degrees steepness. Although the crown was wide, the gulley that the skier was buried in was only 50 feet across. The avalanche broke on facets, some at the ground, others higher in the snowpack. I will have a detailed report later in the week, as will Eric on the fatality on Henderson Mountain. I posted a few photos on the web with more to come.
A lot of reports and observations are streaming into the avalanche center. Some relevant news:
- Natural avalanches were seen again yesterday around Cooke City. We had some large, throaty, whumphs as we skied to the accident site yesterday. Eric’s video from Sunday illustrates the touchy nature of the snowpack.
- Lots of collapsing and cracking down south.
- Very poor stability test scores were reported in the Bridger Range (ECTP 2, Q1).
- Avalanches continue to release at the ground with explosives at Moonlight Basin.
- Slopes that slid earlier in the year are getting reloaded and avalanching again. Fisher Peak outside Cooke City avalanched on Nov 26 an again yesterday. Compare the photos: Nov 26; Jan 2.
We are not out of the woods and should not let our guard down. Dangerous avalanche conditions exist and today the avalanche danger is rated CONSIDERABLE on all slopes in our advisory area.
Since yesterday morning we have posted more photos on the avalanche accidents, plus a few others relating to instability. More will be added today along with a video clip. Check these out at Photos and Videos.
I will issue the next advisory tomorrow morning at 7:30 a.m. If you have any snowpack or avalanche observations, drop us a line at mtavalanche@gmail.com or call us at 587-6984.
EVENTS/EDUCATION
To check out all our education programs: http://www.mtavalanche.com/workshops/calendar
BOZEMAN
Women’s 1-hour Avalanche Awareness Lecture. Wednesday, January 4, 6:30- 8 p.m. at REI.
Snowmobiler Introduction to Avalanches with Field Course. Lectures on Saturday, January 7, with an all day field session Sunday, January 8. Advanced registration IS REQUIRED.
1-hr Avalanche Awareness Lecture. Wednesday, January 11, 6:30-7:30 p.m. at REI.
BIG TIMBER
1-hr Avalanche Awareness Lecture. Tuesday, January 10, 7-8 p.m. at Big Timber High School.
HELENA
1-hr Avalanche Awareness Lecture. Thursday, January 12, 6:30-8:30 p.m. at Exploration Works.
COOKE CITY
1-hr Avalanche Awareness Lecture. Saturday, January 14, 5-6:00 p.m. at Cooke City Community Center.
CODY, WYOMING
Snowmobiler Introduction to Avalanches with Field Course. Lectures on Saturday, January 14 at Mountain Valley Motorsports with an all day field session near Cooke City on Sunday, January 15. Advanced registration IS REQUIRED.
BILLINGS
Snowmobiler Introduction to Avalanches with Field Course. Lectures on Tuesday, January 24 from 6-9 p.m. at Hi-Tech Motor Sports with an all day field session in Cooke City on Sunday, Jan 29. PRE-REGISTER BY JAN 23 at Hi-Tech!! Register with Sharon at 406-652-0090; hitech@hi-techmotorsports.com