Good morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Tuesday, January 22 at 7:30 a.m. Mystery Ranch in partnership with the Friends of the Avalanche Center sponsors today’s advisory which is dedicated to Andrew Greicar who was killed in an avalanche outside of Cooke City ten years ago today. This advisory does not apply to operating ski areas.
A ridge of high pressure is firmly parked over the western US. At 4 a.m. temperatures are in the low 20s under clear skies. Today will be a repeat of yesterday, but slightly warmer: sunny skies, westerly winds 15-30 mph and mountain temperatures reaching the upper-thirties. Sunburns are a greater threat today than avalanches.
Bridger Range Madison Range Gallatin Range
Lionhead area near West Yellowstone Cooke City
Overall the snowpack in southwest Montana is looking pretty good. Pretty good is not perfect, so it’s important to know what to look for in order to stay out of trouble. Even though we have not had any storms since last Tuesday, the winds have been scraping every last molecule of snow onto leeward slopes. On a few of these slopes folks were able to trigger small slides. Over the weekend shallow slabs (less than a foot deep) were triggered off Lionhead Ridge (photo). Outside Cooke City a small, but heavily wind-loaded pocket pulled out near Lulu Pass (photo), and Eric had an unexpected collapse on a wind-loaded slope up Hyalite.
Yesterday, my partner and I rode and skied in the Taylor Fork area of the southern Madison Range. The weakest layer in the snowpack is sugary facets buried a foot deep. In our snowpits they only reacted on a southwest facing hill after applying a bit of force (ECTP 16, photo). This layer is slowly gaining strength and without additional snow it’s unlikely it would avalanche. On the surface another weak layer is forming (photo) as tiny facets grow over a razor thin ice crust. The process is known as radiation recrystallization, a type of near-surface faceting (article), and can become a problem if it gets buried before the sun has a chance to melt it.
Although stability is getting better by the day it’s still possible to trigger a small avalanche on a wind-loaded slope steeper than 35 degrees. Consequently, the avalanche danger is rated MODERATE on this terrain. All other slopes have a LOW avalanche danger.
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.
OTHER RELEVANT STUFF
Small avalanches can be deadly. On Friday, in the Uinta Mountains of Utah a small avalanche killed two boys, 8 and 14 years old, when a cornice they were walking on broke and fractured the slope below. It was very unassuming terrain and is worth the few minutes to look at the pictures and video on the Utah Avalanche Center website. We have a very different snowpack than they do, but it illustrates the risk inherent with small terrain features.
Practice using your beacon. The Friends of the Avalanche Center in partnership with the City of Bozeman Recreation Department recently installed a beacon training site at Beall Park on North Black Avenue. It’s free and easy to use.
Quickly assess the snow. Mark made a short video on how to assess the snowpack given our current conditions. In two minutes he gets all the information he needs to make a good decision.
Tonight in Dillon, the Friends are giving a free 1-hour Avalanche Awareness lecture. It is being held at the U of M Western, Lucy Carson Library, room 202 from 6-7 p.m.
This Wednesday (1/23) and Thursday (1/24) evenings and all day Saturday (1/26), we are teaching an Introduction to Avalanches with Field Course at MSU. For more information and to register, visit: https://www.ticketriver.com/event/4970-introduction-to-avalanches-w--field-course
Next Wednesday (1/30) and Thursday (1/31) evenings and all day Saturday (2/02), we are teaching an Advanced Avalanche Workshop with Field Course at MSU. Registration is required. For more info and to register, visit: https://www.ticketriver.com/event/4974-advanced-avalanche-workshop-with-field-course
In Helena, next Thursday (1/31) at 6:30 p.m., the Friends are giving a free 1-hour Avalanche Awareness lecture at Exploration Works (995 Carousel Way).
In Bozeman, on Wednesday, February 6, REI is hosting a 1-hour Avalanche Awareness lecture for Women. Marcie Hahn-Knoff is teaching. Space is limited and registration is required: http://www.rei.com/event/47916/session/64605