Good Morning. This is Eric Knoff with the Gallatin National Forest Avalanche Advisory issued on Thursday, January 18th at 7:30 a.m. Today’s advisory is sponsored by Alpine Orthopedics and Montana State Parks. This advisory does not apply to operating ski areas.
At 5 a.m. there’s no new snow to report and temperatures are in the upper 20’s to mid-30’s F under partly cloudy skies. Winds are blowing 20-30 mph out of the W-SW. Today, warm and windy conditions will continue as a storm approaches. Temps will warm into the 30’s to low 40’s and winds will remain moderate to strong out of the W-SW. Skies become increasingly cloudy throughout the day and the mountains will see light snow or rain showers by this afternoon. Precipitation increases this evening as the strongest part of the storm moves over the area. The mountains around West Yellowstone and Cooke City will see 3-5” by tomorrow morning while the mountains around Bozeman and Big Sky will see 2-4”. Light snow continues through the day tomorrow with an additional 1-3” possible in the north and 3-5” in the south.
The snowpack in the Lionhead area remains untrustworthy. Weak, sugary facets buried 2-3’ deep still hold the potential to propagate a fracture and produce large slab avalanches (video, photo). Terrain management is the best defense against triggering slides under these types of conditions. Avoiding steep slopes and low angle terrain connected to steeper slopes is a sure fire way to avoid triggering a slide. Although avalanches are becoming harder to trigger without new snow, dangerous avalanche conditions still exist.
For this reason the avalanche danger is rated CONSIDERABLE on all slopes.
Signs of instability such as cracking/collapsing and recent avalanches remain present in the mountains around Cooke City. On Tuesday, separate parties skiing west of Cooke City each got large collapses and one party observed an avalanche that likely released during the day (photo). These are Mother Nature’s clues that avalanches are still possible. The tricky part about this area is many slopes are stable, but a few are not (photo). The easiest way to stay out of trouble is to avoid steep slopes altogether. If you do venture into avalanche terrain, assess the snowpack carefully and take the necessary time to make smart and informed decisions.
For today, human triggered avalanches are possible and the avalanche danger is MODERATE.
The primary avalanche problem in the mountains around Bozeman and Big Sky will be wind loaded slopes. Overnight, strong winds transported snow below upper elevation ridgelines. Wind slabs should be stubborn, but still hold the potential to fail with the proper trigger. Watch for and avoid wind loaded slopes if you’re traveling in steep, upper elevation terrain (photo).
A secondary concern will facets sitting over the Thanksgiving ice crust. This problem is not widespread and appears to be confined to slopes with a shallower snowpack. Yesterday, I skied north of Big Sky and found a poor snowpack structure on mid-elevation slopes around 8,000 ft. We did not experience any signs of instability, but did get unstable results in stability tests (video). This indicates this layer could still be a problem with the weight of new and wind-blown snow.
Something else to look out for will be a fresh layer of surface hoar and near surface facets (photo). These layers formed during the recent dry spell and could be a problem when buried by new snow. The distribution of these layers is unclear, but it will be something to keep in mind once more snow falls.
Today, human triggered avalanches are possible and the avalanche danger is rated MODERATE.
If you get out and have any avalanche or snowpack observations to share, drop a line via our website, email (mtavalanche@gmail.com), phone (406-587-6984), or Instagram (#gnfacobs).
Report: Reas Peak Avalanche Fatality
Our report from the snowmobiler avalanche fatality on January 10 is HERE. A snowmobiler was caught, fully buried and killed in Idaho near Reas Peak in the Centennial Range.
King and Queen of the Ridge
King and Queen of the Ridge, Saturday, February 3rd. A Hike and Ski/Ride-a-Thon fundraising event to support the Friends of the Gallatin National Forest Avalanche Center. Sign up and start collecting pledges HERE.
Upcoming Avalanche Education and Events
BOZEMAN
Tonight, and the 20th or 21st, Introduction to Avalanches w/ Field Day, Info and Register Here
Jan. 22, MAP Brewing Pint Night, 4-8 p.m. MAP donates 50 cents of every pint sold to the Friends of the Avalanche Center.
Jan. 24, 25 and 27, Advanced Avalanche Workshop w. Field Day, Info and Register Here
Feb. 9 and 10, Companion Rescue Clinic, Info and Register
WEST YELLOWSTONE
Jan. 20, Avalanche Awareness, 7-8 p.m. at West Yellowstone Holiday Inn Conference Center
COOKE CITY
Every Friday and Saturday, Current Conditions Update and Avalanche Rescue, Friday 6:30-7:30 p.m. at The Antler's Lodge in January. Saturday anytime between 10-2 @ Round Lake.
Our report from the snowmobiler avalanche fatality on January 10 is HERE. A snowmobiler was caught, fully buried and killed in Idaho near Reas Peak in the Centennial Range.