Good morning. This is Alex Marienthal with the Gallatin National Forest Avalanche Forecast on Sunday, February 25th at 7:00 a.m. Today’s forecast is sponsored by Werner Wealth Management (Advisors with DA Davidson), Bozeman Splitfest and Yellowstone Ski Tours. This forecast does not apply to operating ski areas.
There is 2” of new snow near Cooke City and none elsewhere. This morning temperatures are high 20s F, and today temperatures will reach low to mid-30s F. Wind has been out of the west-southwest at 15-30 mph with gusts of 35-65 mph. Today strong westerly wind will continue at 20-35 mph with gusts of 40-60 mph. Overnight wind will increase prior to heavy snowfall tomorrow. Today light snow is possible in the southern ranges of our forecast area with 1-2” by tomorrow morning near Cooke City and Island Park.
Strong winds have been blowing snow into thick drifts over an already unstable snowpack. Human-triggered avalanches are likely and natural avalanches are possible, especially on wind-loaded slopes. On Friday, a rider near Cooke City triggered a large avalanche, was caught and luckily not buried or injured (Cooke City photos), and a pair near Big Sky triggered two large avalanches from flat terrain nearby (photos). Yesterday north of Cooke City, wind was actively forming thick drifts (video), and we saw a recent avalanche that appeared natural or rider triggered in the previous 24 hours (photos).
Recent avalanches show an unstable snowpack exists and will not improve with wind-loading today (and heavy snow tomorrow). We have seen steady avalanche activity since early January, even during times without new snow or wind (weather and avalanche log). Weak layers buried 2-4 feet deep make up the foundation of the snowpack, and are as weak as we’ve seen. People can trigger large avalanches, potentially from flatter terrain below steep slopes. The best plan is to avoid riding on or below slopes steeper than 30 degrees. Avalanche danger is CONSIDERABLE.
In the Bridger Range and northern Gallatin Range you can trigger a large avalanche that breaks 1-3 feet deep on weak sugary snow, and freshly wind-loaded slopes should be avoided. Although less snow over the last week means recent wind-loading is relatively minimal compared to the rest of the area, we can’t trust this season’s very weak snowpack with even the smallest addition of weight. Avalanches last weekend near Bridger Peak and south of Saddle Peak in the Bridger Range, and on Mt. Bole in Hyalite are examples of the avalanche potential.
On non-wind-loaded slopes the likelihood of a slide is lower, but consequences are similar. Before traveling in avalanche terrain carefully assess the snowpack and identify areas to avoid. Choose smaller, simple slopes with clean runouts and no wind-loading. Avoid wind-loaded slopes, and complex terrain with terrain traps such as cliffs, trees or confined gullies. As a final check before committing to steep slopes, do a quick stability test. Look for signs of instability and be ready to change plans if you see any red flags. Avalanche danger is CONSIDERABLE on wind-loaded slopes and MODERATE on non-wind-loaded slopes in the mountains near Bozeman.
Watch Ian’s video from the Throne and Dave’s video from Hyalite for more travel and snowpack assessment tips during these conditions.
If you venture out, please fill an observation form. 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 via 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.
Friday evening and Saturday (tonight and tomorrow), February 23 and 24. Companion Rescue Course. More information and registration HERE.
Friday evening and Saturday, March 1 and 2. Companion Rescue Course. More information and registration HERE.
March 8-10. Bozeman Splitfest. Check the Bozeman Splitfest website for event details and avalanche education opportunities offered by the Friends of the Avalanche Center.
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.
On Thursday Ian rode in the Independence Mine area (up the Main Boulder, outside our advisory area) to check out the snowpack conditions before the Sweet Grass County Recreation Association Poker Ride. Watch his video for a snowpack update. Avoiding riding on and staying out from under slopes steeper than 30 degrees would be a wise choice if you’re headed up to that area.