Good morning. This is Alex Marienthal with the Gallatin National Forest Avalanche Forecast on Saturday, March 23rd at 7:00 a.m. Today’s forecast is sponsored by Spark R&D and Avalanche Alliance. This forecast does not apply to operating ski areas.
This morning, there is no new snow, temperatures are mid-20s to low 30s F, and wind is southwest-west at 10-25 mph with gusts of 25-35 mph. Today an approaching cold front will bring snow showers and a chance for thunder this afternoon. Temperatures will reach mid-30s to low 40s F with wind out of the southwest at 10-25 mph. Near West Yellowstone light snow is possible this morning, and throughout the forecast area snow will fall late this afternoon through tomorrow. By morning the mountains could get 3-5” of snow with more tomorrow.
All Regions
Buried weak layers of sugary snow continue to create the main avalanche concern, and a person can trigger large to very large avalanches that break multiple feet deep and hundreds of feet wide. Additionally, slabs of snow 1-2 feet deep can be triggered where moderate winds drifted 1-4” of recent snow into thicker slabs. Loose wet avalanches in the recent snow are not likely with today’s cloud cover, but above freezing temperatures create a slight chance and make it worth mentioning these small, but powerful slides.
Steer clear of fresh drifts on steep slopes. A common sign these are unstable is seeing cracks shoot across the snow from your skis or feet. Be cautious of wet loose avalanches if you find a moist snow surface. While these two potential avalanche types are relatively small, they are forceful and especially harmful if they carry you into trees, rocks or over cliffs, and can be deep enough to bury a person.
Avalanches breaking deeper on sugary weak layers may be less likely, but they will be large and highly consequential. Most recently, last Tuesday two skiers near Mt. Blackmore triggered this type of avalanche. One of the skiers was caught and injured, and rescued by GCSAR with a helicopter (details and photos). Last week there was a huge remotely triggered slide in the Absarokas (details), and a big slide broke naturally on the north face of Mt. Blackmore (details).
This video from early January reminds us of the very poor foundation of the snowpack supporting all the snow that has since fallen. The current potential hazard is made clear by an impressive list of avalanches over the last 2-3 months (avalanche log). Assessing the stability of these deeply buried weak layers is difficult. To manage this problem, the best strategy is careful terrain selection and sticking to safe travel practices.
Choose smaller and simpler slopes with minimal wind-loading and clean runouts free of trees, cliffs, rocks or confined gullies. Only expose one person at a time to steep slopes, watch your partners from a safe spot while they’re on those slopes, and make sure everyone carries rescue gear (avalanche beacon, shovel, and probe). Today, heightened avalanche conditions require you to identify and avoid areas of concern if you plan to travel in or near avalanche terrain. The avalanche danger is MODERATE throughout the forecast area.
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.
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.
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