Good Morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Wednesday, March 29th at 7:00 a.m. Today’s advisory is sponsored by Grizzly Outfitters in partnership with Friends of the Avalanche Center. This advisory does not apply to operating ski areas.
Under partly cloudy skies temperatures are in the low 20s and ridgetop winds are blowing 10-15 mph with gusts of 20-25 out of the W-SW. Clouds will increase today as temperatures rise into the upper 30s with increasing southwest winds. By early evening rain will fall in the valleys and snow at the upper elevations. Freezing lines will be 6500’ in the south and near 7500’ in the north. By morning there will be 3-4” of new snow in the mountains near West Yellowstone and Cooke City and 1-2” elsewhere. Snowfall will continue through Thursday.
Bridger Range Madison Range Gallatin Range Lionhead area near West Yellowstone Cooke City
Today is a day of transition as another storm approaches. This morning sun will dampen the snow surface creating the possibility of wet loose avalanches. This danger will be short lived as increasing cloud cover and wind will keep significant melting at bay. Later this afternoon rain may occur at lower elevations. Rain on snow is bad and can quickly trigger widespread avalanches.
The snowpack has a thick, supportable crust under the new snow creating generally stable conditions. Yesterday, skiers on a late day tour of Gallatin Peak noticed a few wet, loose avalanches running on this crust (photo) and found drier, powdery conditions at the upper elevations. They noted light winds blowing snow at the ridgelines and plenty of snow available to drift. This same party texted me at 0630 this morning from Hyalite confirming variable winds and their loading potential. (Yes, this is a first.) In the last few days, given safe avalanche conditions at higher elevations folks have been hitting steep, exposed lines. Today an extra dose of caution is needed since a wind slab could fatally knock you off a cliff or down a face (photo).
Light winds are moving snow and today they are forecasted to increase. Throughout our advisory area the dry snow avalanche danger is rated MODERATE on all wind-loaded terrain and LOW everywhere else. The wet snow avalanche danger will rise to MODERATE on slopes getting sun and if rain occurs, the danger will rise even more.
I will issue the next advisory tomorrow morning by 7:30 a.m. Our last advisory of the season will be Sunday, April 9th.
We rely on your field observations. Send us an email with simple weather and snowpack information along the lines of what you might share with your friends: How much new snow? Was the skiing/riding any good? Did you see any avalanches or signs of instability? Was snow blowing at the ridgelines? If you have snowpit or test data we'll take that too, but this core info is super helpful! Email us at mtavalanche@gmail.com or leave a message at 406-587-6984.
MAY 4: Give Big Gallatin Valley
The Friends of the Avalanche Center are one of the recipients of the Give Big Gallatin Valley campaign. It is a 1-day fundraising event for local non-profits on May 4, so mark your calendars. The Friends will send reminders as the day approaches: https://www.givebiggv.org/organizations/friends-of-the-gallatin-national-forest-avalanche-center