Good Morning. This is Eric Knoff with the Gallatin National Forest Avalanche Advisory issued on Friday, March 31th at 6:45 a.m. Today’s advisory is sponsored by Community Food Co-op and Spark R&D. This advisory does not apply to operating ski areas.
Since yesterday morning 1-2” of snow fell in the mountains. At 5 a.m. temperatures range from the mid-20s to low 30s F under mostly cloudy skies and winds are blowing 15-25 mph out of the E-NE. Today, east winds will continue which will reduce the potential for mountain snow. Skies will be mostly cloudy this morning, but become partly cloudy buy this afternoon. Temperatures will warm into the upper 20s to high 30s F and winds will continue to blow 15-25 out of the E-NE. A ridge of high pressure builds over the area tonight producing sunny and warm conditions tomorrow.
Yesterday, loose snow avalanches were observed in the Bridger Range (photo), northern Gallatin Range (photo) and northern Madison Range. In upper elevation terrain, these slides would be considered dry loose avalanches. On mid to lower elevation slopes, mainly in the Bridger Range, these slides occurred as wet loose avalanches. Either way, the new snow was running easily on the firm ice curst that formed prior to the storm.
Although the new snow had a day to settle and bond to the underlying bed surface, loose snow avalanches will be possible in steep terrain today. This problem will be a growing concern once the sun comes out. Pay attention to changing conditions and don’t be afraid to change plans if instability is on the rise.
An additional problem will be wind slabs near upper elevation ridgelines. Winds shifted to the E-NE yesterday, which will create unusual loading patterns. With plenty of snow available for transport, mainly above 9,000 ft. wind slabs will be something to look out for. These won’t be real touchy to human triggers, but they could to fail under the weight of skier or rider.
Today, the dry snow avalanche hazard is MODERATE in upper elevation terrain. The wet snow avalanche hazard will start out LOW, but rise to MODERATE as the day progresses.
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