GNFAC Avalanche Forecast for Sun Apr 5, 2020

Not the Current Forecast

Good Morning. This is Alex Marienthal with the Gallatin National Forest Avalanche Forecast on Sunday, April 5th at 7:00 a.m. This is our 127th and last daily forecast of the season. Today's forecast is dedicated to you, everyone that sent in observations, read the advisories, took an avalanche class, or donated money, time or gear. Our success is directly related to community support and the Forest Service. Thank you for another great season.

Mountain Weather

Yesterday morning the mountains near West Yellowstone and Cooke City got an inch of snow with none elsewhere. Overnight, wind was south-southwest at 15-25 mph with gusts to 35 mph. This morning temperatures are 20s F and wind is southwest at 10-20 mph. Today temperatures will reach mid-30s F under partly cloudy skies with southwest wind at 15-30 mph. Light snow showers will drop a trace to an inch of snow in the southern ranges today, and another 1-2” is possible in the mountains by morning.

Snowpack and Avalanche Discussion

All Regions

Yesterday a skier triggered a thin wind slab on Beehive Peak which caught and carried a four-legged group member (photos and details). All were unharmed. Although seemingly small, a shallow slab can carry you over cliffs or into trees. Today you can trigger fresh wind slabs that formed the last couple days with moderate southwest wind. Be cautious of wind loaded slopes, and avoid terrain where any size slide has large consequences.

Larger avalanches can break 2-3 feet deep on buried weak layers. Yesterday in the northern Gallatin Range a snowmobiler triggered a 2 foot deep slide that likely failed on buried surface hoar, facets or a crust. All of which have produced avalanches, collapsing and unstable test results for the last week (avalanche log). Dig a few feet to look for weak layers and avoid slopes where you suspect they exist. Weak layers 2-3 feet deep have consistently been found and breaking in stability tests from the Bridger Range (photo) to West Yellowstone (photo, photo).

Also avoid slopes where you can trigger wet avalanches if the snow becomes wet, and stay away from large cornices (photo). As Doug explains in his recent video, even though things may look good there are various hazards and stability can change quickly. Today avalanches are possible and avalanche danger is MODERATE.

Since Wednesday there were two tragic avalanche fatalities in Wyoming and Idaho (report, report), and in the last two weeks two avalanche accidents in Colorado required heli-evac for serious injuries (report, report). All of these accidents occurred during moderate avalanche danger. A lot of people are out skiing and riding, and distancing themselves into new and untracked terrain. Please make conservative choices. Choose terrain where a slide will not carry you through rocks, over cliffs or into trees, no matter how certain you are of stability. Avoid avalanche terrain entirely to greatly reduce your risk of being injured or killed. Please consider the greater risk to rescuers, EMS resources and yourself at this time.

We will post general weather and avalanche bulletins every Monday and Friday through April. Please continue to send us your observations. You can fill out an observation form, email us (, leave a VM at 406-587-6984, or Instagram (#gnfacobs). We greatly appreciate your support.

Closures and Stay-at-home Order

A Stay at Home order is in effect for the State of Montana due to COVID-19. This order specifically discourages “outdoor recreation activities that pose enhanced risks of injury or could otherwise stress the ability of local first responders to address the COVID-19 emergency (e.g., backcountry skiing in a manner inconsistent with avalanche recommendations or in closed terrain)”.

Bridger Bowl is closed and advises against uphill travel which could place first responders at risk. Backcountry conditions exist. There is no avalanche control or ski patrol rescue. Please do not loiter or congregate in the parking lots.

Park County is requesting anyone who is not a permanent resident or provider of essential service to avoid travel to Cooke City/ Silvergate. This includes both single day and overnight visitors.

Hyalite Canyon is closed to vehicle traffic and will reopen on May 15th. This is the regular spring use closure.

Avalanche Education & Events

Give Big Gallatin Valley is April 30th - May 1st. The Friends of the Avalanche Center are participating again this year and we’d really appreciate your support!

If you like to plan ahead, you can put the PowderBlast on your calendar for next fall (Friday, October 23rd, 2020). This event is always a good time and is our biggest fundraiser of the year. Hope to see you there!

See our calendar for online classes offered this evening and next week.

The Last Word

Thank you for your support. Ride safe.

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