GNFAC Avalanche Forecast for Sun Apr 7, 2024

Not the Current Forecast

Good morning. This is Alex Marienthal with the Gallatin National Forest Avalanche Forecast on Sunday, April 7th, at 7:00 a.m. Today’s forecast is sponsored by Bridger Bowl, Cooke City Motorsports and Advanced Innovation. This forecast does not apply to operating ski areas.

Mountain Weather

The Bridger Range has 8-19” of new snow since yesterday morning, Hyalite got 7”, Cooke City and Big Sky got 4”, and 1-3” fell near West Yellowstone and Island Park. Temperatures are teens to 20 F. Yesterday wind was west-northwest at 15-25 mph with gusts of 35-50 mph, and overnight wind decreased to 5-15 mph with gusts of 15-30 mph. Today temperatures will reach high 20s to low 30s F with west-northwest wind at 10-25 mph. Snow showers will continue today and tonight. By morning expect 6-10” in the Bridger Range, 3-6” near Big Sky and Cooke City, and 1-2” near West Yellowstone and Island Park.

Snowpack and Avalanche Discussion

New snow creates the avalanche hazard today, primarily where it is drifted into thicker slabs. Watch for blowing snow and cracks shooting across the snow surface as signs where fresh, unstable slabs are forming. Last week’s warm temperatures made the snowpack wet or moist to the ground on most slopes, and now the snowpack has a frozen supportable crust below the new snow. This melt-freeze crust might make new snow and fresh wind slabs slide easier.

If you ride or cross steep slopes, choose slopes without fresh drifts and without terrain traps like cliffs or trees where even a small slide would have large consequences. Carefully assess how the new snow is bonding to the old snow surface. Expect this instability to change from slope to slope. And, with more snow today and temperatures near freezing (melting) the new snow might become more unstable later in the day.

Avalanches breaking on deeper weak layers are unlikely, but not out of the question on higher, shady slopes that didn’t get as wet last week. Dig down a few feet to check for buried weak layers if you are getting onto steep slopes.

Today the avalanche danger is MODERATE near Bozeman, Big Sky and Cooke City.

Near West Yellowstone and Island Park the main concern is where new snow is drifted into thicker slabs (video). These wind slabs could easily slide on the hard melt-freeze crust below. On non-wind-loaded slopes the few inches of new snow will present minimal hazard, and avalanches breaking on deeper weak layers are unlikely.

Watch for cracking across the snow surface as a sign unstable drifts exist, and choose slopes without trees, cliffs or other terrain traps that would increase the chances of being injured in even a small slide. Although deeper avalanches are unlikely, they are not impossible. If you are riding steep, consequential slopes it is a good idea to dig down a few feet to look for weak layers and assess snow stability. Even with generally stable conditions it is essential to carry avalanche rescue gear (beacon, shovel, probe) and only expose one person at a time to steep slopes. 

Avalanche danger is MODERATE on wind-loaded slopes and LOW on all other slopes near West Yellowstone, Island Park, and in the southern Madison and southern Gallatin ranges.

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 (, phone (406-587-6984), or Instagram (#gnfacobs).

Upcoming Avalanche Education and Events

Hyalite Road Closure: Hyalite road is closed to ALL MOTORIZED VEHICLES until the morning of May 16. This is a regular annual road closure to reduce road damage during the spring thaw. Bicycle and foot traffic are allowed. Contact the Bozeman FS Ranger District for more info.

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.

The Last Word

The total number of avalanche deaths in the US stands at 13. On March 29, a snowboarder was killed on Mt. St. Helens when a cornice he was standing on broke and triggered the slope below.

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