Good morning. This is Alex Marienthal with the Gallatin National Forest Avalanche Forecast on Monday, February 5th at 7:00 a.m. Today’s forecast is sponsored by Mystery Ranch and Basecamp Gallatin and Yamaha. This forecast does not apply to operating ski areas.
AVALANCHE WARNING
The Gallatin National Forest Avalanche Center is continuing a Backcountry Avalanche Warning for the Centennial Mountains in Island Park, the Lionhead area near West Yellowstone, and the southern Madison and southern Gallatin ranges. New snow and wind are forming drifts and overloading an exceptionally weak snowpack, creating very dangerous avalanche conditions. Human-triggered and natural avalanches are likely. Avoid avalanche terrain and avalanche runout zones. This warning will expire or be updated by 6:00 a.m. on Tuesday, February 6th.
Yesterday the mountains near Island Park received 3-5” of new snow and 1-2” fell elsewhere. Overnight, wind increased out of the south-southwest at 15-35 mph with gusts of 35-68 mph. Wind will continue from the south-southwest at 10-20 mph with gusts to 35 mph. Temperatures are teens to mid-20s F this morning, and today will reach high 20s to mid-30s F. Snow is falling near West Yellowstone and Island Park and will continue through today. By tomorrow morning the mountains near Bozeman, Big Sky and Cooke City might get 1-3”. Near West Yellowstone 4-8” are possible with 10-16” near Island Park.
Avalanche Warning
Wind increased overnight and drifted new snow into heavier slabs on an unstable snowpack. Today, more new snow and wind will continue to grow drifts, and make natural and human-triggered avalanches likely. Over the last two days in the southern Madison Range multiple groups of skiers experienced large collapses of the snowpack (observation 1, observation 2, observation 3). Near Island Park, yesterday a rider noted a foot of new snow, strong wind and large collapses (observation), and on Friday a rider triggered an avalanche and was partially buried while riding solo. He was thankfully able to dig himself out unharmed (observation). Conditions will be more dangerous today. Avalanches can be triggered from flatter terrain connected to steeper slopes above. Plan your day carefully. Choose routes that avoid travel on or underneath slopes steeper than 30 degrees. The avalanche danger is HIGH.
Over the last couple days the mountains near Bozeman, Big Sky, and Cooke City received 5-8” of new snow (0.4-0.7” of snow water equivalent). Strong wind is drifting this snow into thicker slabs that will easily avalanche. Avalanches will probably break deeper on weak layers buried 1-2 feet deep, and can be triggered from flatter terrain below steep slopes.
Yesterday, in Beehive Basin skiers saw recent natural and skier-triggered loose snow slides (photo and details), a skier south of Cooke City sent this photo of a recent large natural avalanche, and north of Cooke City we found unstable buried weak layers below a hard slab of snow (video). Previous avalanche activity near Cooke City was widespread and shows the type of avalanches a person can trigger (weekly update video). Earlier this week, ice climbers approaching a climb triggered a large slide from 150 feet away (observation), and a rider was partially buried near Round Lake (video).
This season’s snowpack has been exceptionally weak, and we have seen avalanches every time there is a couple inches of new snow. With the addition of moderate to strong wind today, human-triggered avalanches are likely and natural avalanches are possible. Avoid slopes steeper than 30 degrees and be extra cautious crossing below. The avalanche danger is CONSIDERABLE.
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.
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.
POSTPONED: King and Queen of the Ridge, February 3rd. Bridger Bowl’s community event series events this weekend are postponed, including King & Queen - stay tuned, details coming soon.
9-10 February. Companion Rescue Course. More information and registration HERE.
9-10 February. Dillon Montana Avalanche Fundamentals. More information and registration for the MOTORIZED SECTION and NON-MOTORIZED SECTION
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.
This year's snowpack is not to be trifled with. Read Doug’s important thoughts about the unusually unstable snowpack on this recent Instagram post.