Good morning. This is Eric Knoff with the Gallatin National Forest Avalanche Advisory issued on Monday, February 9, at 7:30 a.m. Yellowstone Club Community Foundation in partnership with the Friends of the Avalanche Center sponsors today’s advisory. This advisory does not apply to operating ski areas.
Snow started falling at 5 am this morning and the mountains have picked up 1-2 inches of new snow. At 6 am, mountain temperatures range from the upper 20s to mid-30s F and winds are blowing 15-25 mph out of the W-SW with gusts near 50 mph being recorded in Hyalite and Big Sky. Today, temps will warm into the upper 30s to low 40s F under cloudy skies. Winds will continue to blow 15-25 out of the W-SW with stronger gusts along the ridgelines. A weak storm system will continue to impact the area through the day. The northern mountains will likely receive an additional 1-2 inches of snow by this afternoon while the southern mountains will pick up 2-3 inches. Unsettled weather is likely through tomorrow.
Southern Madison Range Southern Gallatin Range
Lionhead Area near West Yellowstone Cooke City
The ferocious wind storm that hammered southwest Montana over the past few days has ended, but not without doing a number on the snowpack (photo). Many slopes have been scoured to the dirt, while others hold large pillows of wind drifted snow. These heavily wind loaded slopes will be the ones to watch out for today (photo).
Warmer temperatures will allow wind slabs to heal quickly. However, caution should be exercised when traveling in and around wind loaded terrain. Fortunately, wind loaded slopes can be easily recognized and avoided.
In search for the last scraps of powder, skiers and riders may encounter slopes with a thin layer of facets or surface hoar buried 1-2 feet deep. Doug found this layer yesterday while riding in the Taylor Fork area (video, photo) and Mark and I found it in Teepee Creek on Saturday. This layer has a scattered distribution (video), which warrants a quick snowpit and stability test before committing to steep terrain.
Today - sporadic wind slabs and weak layers make human triggered avalanches possible on wind loaded slopes and slopes steeper than 35 degrees which have a MODERATE avalanche danger. All other slopes have a LOW avalanche danger.
Bridger Range Northern Madison Range Northern Gallatin Range
In the northern ranges, 1-2 inches of new snow combined with moderate winds out of the west-southwest will make wind slabs today’s primary avalanche concern. The new snow is wet and heavy which will allow it to bond well to the old snow surface and make it more difficult for the wind to transport. However, in isolated areas fresh wind slabs may be reactive to the weight of a skier or rider. This problem will stay confined to upper elevation, leeward terrain and will only exist within the new snow. Fresh wind slabs will remain relatively small in size, but have the potential to be dangerous, especially in steep, high consequence terrain.
Apart from wind loaded slopes, there are a few layers buried 1-2 feet deep. Yesterday, skiers up Hyalite got unstable results in stability tests on a thin ice crust buried just over a foot deep. Without a recent load this isolated instability shouldn’t be much of a problem, but it’s worth keeping an eye out for.
Today – human triggered avalanches are possible on wind loaded slopes steeper than 35 degrees which have a MODERATE avalanche danger. All other slopes have a LOW avalanche danger.
Doug will issue the next advisory tomorrow morning at 7:30 a.m. If you have any snowpack or avalanche observations drop us a line at mtavalanche@gmail.com or call us at 587-6984.
KING AND QUEEN OF THE RIDGE
Saturday, February 14th is the 13th Annual King and Queen of the Ridge Hike/Ski-a-thon fundraiser at Bridger Bowl to support avalanche education in southwest Montana. Collect pledges for each lap of hiking to the ridge and skiing back down. 100% of the proceeds go to the Friends of Gallatin National Forest Avalanche Center. Hike as an individual or form a team of your workmates or playmates or family! Prizes are awarded for Team and Individual categories. Make a Pledge. Sign Up and More Info.
AVALANCHE EDUCATION and EVENTS
Take a look at our Education Calendar for all classes being offered.
Woman's 1-hour Avalanche Awareness, Bozeman, REI, 6:30 p.m., Wednesday, February 11.
Companion Rescue Clinic, Bozeman, REI, 6-8 p.m., Friday, February 20 and 10 a.m.-2 p.m. on Saturday, February 21 (field location TBD). Pre-registration is required: www.rei.com/stores/bozeman.html
1-hour Avalanche Awareness, West Yellowstone, Holiday Inn, 7 p.m., Saturday, February 21.