Good morning. This is Doug Chabot with the Gallatin National Forest Avalanche Forecast on Thursday, February 15th at 7:00 a.m. Today’s forecast is sponsored by Klim and Mystery Ranch. This forecast does not apply to operating ski areas.
AVALANCHE WARNING
The Gallatin National Forest Avalanche Center is issuing a Backcountry Avalanche Warning for the entire forecast area: The Bridger, Gallatin and Madison Ranges, and the mountains around Cooke City, West Yellowstone and Island Park. It is snowing and is forecasted to continue with 6-12” in the southern ranges and 3-6” in the north. Strong southwest wind is blowing snow and creating drifts. Our snowpack is weak and unstable and triggering avalanches is very likely. Avoid avalanche terrain and avalanche runout zones. Very dangerous avalanche conditions exist. The avalanche danger is HIGH on all slopes.
This warning will expire or be updated by 6:00 a.m. on Friday, February 16th.
At 6 a.m. 2-4” of snow has fallen around Bozeman, 5” around Big Sky, and 5-8” in the south. Snowfall is predicted to continue in pulses today and tonight. Accompanying the snow is strong wind, mostly from the southwest, except the Bridger Range which is blowing east. Wind speed is averaging 15-20 mph with gusts of 35 mph, and West Yellowstone and Island Park measuring gusts up to 57 mph. Temperatures are currently in the high teens F. By tomorrow morning another 6-10” will fall in the south and 3-6” in the northern mountains.
All Regions
Avalanche Warning
It is very dangerous in the backcountry. We have issued an Avalanche Warning and the danger is rated HIGH on all slopes throughout our forecast area.
Mere inches of new snow are triggering avalanches naturally. With strong southwest wind, slopes will be loaded and drifted which adds more weight to our fragile and unstable snowpack. Yesterday, Ian and I rode into Taylor Fork and toured Sage Basin to Cabin Creek. We saw a large natural avalanche that broke a couple days ago. It propagated 700+ feet wide. On an adjacent slope was a smaller but deep avalanche, likely triggered from the bottom of the slope by a snowmobiler on Tuesday (observation). Ian succinctly stated in his video, “The equation is simple: recent avalanches, plus people triggering avalanches, plus more snow, means the avalanche danger will spike.” It’s not very complicated.
Stay out of avalanche terrain and stay away from the bottom of slopes. To help, use the 30-20 rule: measuring with an inclinometer, any slope steeper than 30 degrees is avalanche terrain, and runout zone angles should be under 20 degrees (instruction video).
Triggering avalanches from below or adjacent to a slope is scary and dangerous. A whumpf is the sound of a weak layer collapsing which can travel onto a steep slope and avalanche above you. Typically this type of instability is short lived and rare, but not this year. Dave got surprised on Monday when he triggered an avalanche at Buck Ridge from afar on the flats (observation, video).
In the last 10 days, the avalanche activity log has over 50 entries of avalanche activity and other signs of instability. It is sobering. We are lucky no one has died in an avalanche. Going in the backcountry is like entering enemy territory with insurgents hiding and watching.
If you get out please submit an observation. It does not need to be technical. Did you see any avalanches? How much snow is on the ground? Was the wind moving snow? Simple observations are incredibly valuable. You can also contact us by email (mtavalanche@gmail.com), phone (406-587-6984), or Instagram (#gnfacobs).
Upcoming Avalanche Education and Events
Our education calendar is full of awareness lectures and field courses. Check it out: Events and Education Calendar.
Every weekend in Cooke City: Friday at The Antlers at 7 p.m., Free Avalanche Awareness and Current Conditions talk, and Saturday from 10 a.m.-2 p.m. at Round Lake Warming Hut, Free Rescue Practice.
Loss in the Outdoors is a support group for those affected by loss and grief related to outdoor pursuits. Check out the link for more information.
A skier and a snowmobiler lost their lives in avalanche accidents in Colorado and Wyoming this week. Read accident reports to learn from these tragedies.
In Alex’s recent article for the Montana Snowmobile Association, he revisits our concerns about the abnormally weak snowpack in Southwest Montana. In the last week, there were nearly 50 entries in our Avalanche Activity Log. Do not mess with this snowpack!