GNFAC Avalanche Forecast for Thu Feb 4, 2021

Not the Current Forecast

Good Morning. This is Doug Chabot with the Gallatin National Forest Avalanche Forecast on Thursday, February 4th at 7:15 a.m. Today's forecast is sponsored by Mystery Ranch and World Boards. This forecast does not apply to operating ski areas.

Mountain Weather

In the last 24 hours 4-6” fell in the Bridger Range and Hyalite and 3-5” fell around Big Sky, West Yellowstone and Cooke City. Wind is from the W-NW averaging 15-20 mph with gusts of 40 mph. Wind speed and direction won’t change today.  Mountain temperature is 10F and will rise into the low 20s. It will snow again tonight with 4-6” expected by morning.

Ever the optimist, I think the Bridger Range could get more snow than 6” because they are in a snowfall wringing, moist, northwest flow. Just sayin’.

Snowpack and Avalanche Discussion

In the mountains surrounding Bozeman, last night’s 4-6” of new snow (measuring .3-.5” of snow water equivalent-SWE) and gusty west to northwest wind will keep the potential for triggering avalanches alive and well. The new snow will be blown into drifts which will likely crack and avalanche on steep slopes. Additionally, in the last 36 hours almost 1 inch of SWE has fallen, which is a decent amount of weight to put on a snowpack that has poor structure and is seen as untrustworthy. Ian was in the Bridger Range on Tuesday and found a thin, weak, faceted snowpack (Throne video). Skiers on Mt. Blackmore yesterday found the new snow bonding well to the old, but the sugary facets at the ground are still concerning. Stay clear of avalanche terrain; the snowpack is under new stress from the new snow and wind-loading. Triggering avalanches is likely. For today the avalanche danger is rated CONSIDERABLE on all slopes.

Last night a few inches fell around Big Sky while most of the snowfall arrived yesterday morning near West Yellowstone and Cooke City. In general, the weight of new snow (.5-.7” SWE in 36 hours) and wind-loading makes it possible to trigger slides today, but it is not a sure thing. That makes navigation a bit tricky. Many avalanches last weekend (full list here, Lionhead video of major avalanche cycle) and a snowmobile triggered slide on Monday at Lionhead (details) broke on weak layers near the ground (sugary facets) or midpack (2’ from the surface). Noteworthy slides include a very large skier-triggered avalanche on Ernie Miller Ridge near Bacon Rind on Saturday (video, details) and another large avalanche on the Fin outside Cooke City. Avalanches will be more difficult to trigger after last week’s wallop, but two things should be considered: first, the faceted (sugary) weak layers that the avalanches broke on are still 

there, and second, the new snow and wind-loading has added weight that will keep these layers from becoming dormant. Avoid avalanche terrain entirely if you see signs of instability such as cracking, collapsing or fresh avalanches. For today the avalanche danger is rated MODERATE.

If you get out, please send us your observations no matter how brief. You can submit them via our website, email (, phone (406-587-6984), or Instagram (#gnfacobs).

King and Queen Fundraiser

February 6th and 7th -- AWESOME PRIZES for individuals who raise over $500! Two pairs of skis, Airbag Avy pack, and more! Deadline for fundraising is 1:15 p.m. Sunday, Feb. 7. No racing is necessary to compete for the fundraising prizes. Info is HERE.

Upcoming Avalanche Education and Events

See our education calendar for an up-to-date list of all local classes. Here are a few select upcoming events and opportunities to check out:

Every Saturday in Cooke City, FREE snowpack update and rescue practice at the Round Lake Warming Hut between 10 a.m. and 3 p.m. Poster with More Info.

February 5 and 6, Women's Companion Rescue Clinic with SheJumps. Registration HERE.

February 19 and 20, Companion Rescue Clinic. Registration HERE

February 26 and 27, Women's Companion Rescue Clinic with SheJumps. Registration HERE.

The Last Word

On Saturday, January 30th a skier died in an avalanche in Utah outside the Park City Ski Area boundary. The search and recovery efforts were initially delayed due to dangerous avalanche conditions and were completed on January 31st. We are deeply saddened by this loss of life. Preliminary details are available here.

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