Good morning. This is Mark Staples with the Gallatin National Forest Avalanche Advisory issued on Friday, January 24 at 7:30 a.m. A Montana FWP Recreation Trails Grant sponsors today’s advisory. This advisory does not apply to operating ski areas.
This morning temperatures were in the 20s F with an inversion in a few low lying areas. In most places winds increased some since yesterday and were blowing westerly 15-20 mph gusting to 30 mph. Today will have more warm and sunny weather. High temperatures should be near freezing and winds will blow 10-20 mostly from the W and NW.
Bridger Range Gallatin Range Madison Range
Lionhead area near West Yellowstone
Increased winds yesterday transported the few inches of new snow and created some shallow but reactive wind slabs triggered by both the Big Sky and Bridger Bowl ski patrols. These wind slabs may be easy to trigger, but they are not widespread and should be easy to see and avoid.
A bigger problem is a layer of faceted snow about a foot above the ground now buried about 3-4 feet deep. Triggering avalanches on this layer has gotten harder for two reasons. (1) It is generally covered by a thick slab of hard snow. (2) The lack of any significant new snow during the last 7-10 days has given this layer a breather. Unfortunately this faceted snow formed rather quickly during cold weather in early December but will take a long time to heal and gain much strength. A layer like this one will be an issue for the most of this season especially any time we get a big load of new snow.
In the Bridger Range this layer is weakest and mainly a concern in steep, rocky areas. On Tuesday my partner and I went looking for this layer near Frazier Lake. In many meadows and safe places to dig a snowpit, this layer is strong and often does not break in stability tests. We tied into a rope and dug a pit in a steep, starting zone (photo) where it was obvious and broke cleanly in stability tests. In most other areas near Bozeman, Big Sky, and West Yellowstone, this layer is widespread. It exists on most slopes and is easy to find.
Until we get more snow to add weight to the snowpack, the avalanche danger remains MODERATE. With a faceted layer lurking in the snowpack, this danger level should not be taken lightly because this layer has proven time and time again its willingness to fracture and produce avalanches.
Cooke City
The snowpack near Cooke City had the same layer but it is now buried over 6 feet deep and no longer a problem on many slopes. Unfortunately it lingers on some slopes and can produce large avalanches in isolated areas like one that buried a snowmobiler a week ago. Doug wrote a full accident report worth reading and a short article describing this low probability/high consequence type of avalanche problem.
The odds of triggering a similar avalanche have decreased each day during the last week. Slopes most likely to slide are ones with a relatively thinner snowpack like one that was triggered last Saturday above Sheep Creek. Look closely at this photo and notice how the snowpack tapers to bare ground not far above the crown. Today with this faceted layer lurking in a few areas the avalanche danger is rated MODERATE on wind loaded slopes and on slopes steeper than 35 degrees. Slopes without a wind load and less than 35 degrees in steepness 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.
GVSA POKER RIDE on BUCK RIDGE
This Saturday, the Gallatin Valley Snowmobile Association is having their annual Poker Ride on Buck Ridge. Dale Gullett will be teaching transceiver skills, so stop on by. Registration will be from 9 AM - noon at the Buck Ridge parking lot just south of the Corral Bar and Steakhouse on Highway 191 (5 miles South of Big Sky). Each hand costs $5.00. The last draw will be held at the Corral at 4:00 PM. Chili and cornbread will be provided. If you have any questions, contact Wes at (406) 600-6063.
ANDROID APP
If you have an android phone or tablet, you can download our new free app. It’s a slick way to get the advisory. Search Google Play for GNFAC. An iOS version is coming soon. Stay tuned.
EVENTS/EDUCATION
January 25, WEST YELLOWSTONE: Saturday, 7-8 p.m. at Holiday Inn, 1-hour Avalanche Awareness lecture.
January 29, 30 & February 1, BOZEMAN : Wednesday and Thursday 7-9:30 p.m.; all day Saturday in field, Advanced Avalanche Workshop with Field Course. Pre-registration is required: https://www.ticketriver.com/event/7114-asmsu-advanced-avlanche-workshop-w-field-course
January 31, February 1, BOZEMAN: Friday 6-8 p.m., Saturday 10-2 p.m; Companion Rescue Clinic. Pre-registration is required: www.rei.com/stores/bozeman.html
February 6, BOZEMAN: Thursday, 6-8 p.m., Beall Park; Women’s Specific Avalanche Awareness Class and Transceiver Practice.
February 8, BUCK RIDGE: Saturday, 10 a.m. to 4 p.m., Companion Rescue Clinic for Snowmobilers, Pre-Registration is required. https://www.ticketriver.com/event/9446
February 8, WEST YELLOWSTONE: Saturday, 7-8 p.m., Holiday Inn, 1-hour Avalanche Awareness lecture.
February 12, BOZEMAN: Wednesday, 6:30-7:30 p.m., MSU Procrastinator Theater, Sidecountry IS Backcountry lecture.
More information our complete calendar of events can be found HERE.