Good morning. This is Mark Staples with the Gallatin National Forest Avalanche Advisory issued on Friday, February 25, at 7:30 a.m. Northern Lights Trading Company in cooperation with the Friends of the Avalanche Center, sponsors today’s advisory. This advisory does not apply to operating ski areas.
Since yesterday only 1-2 inches of snow fell in the mountains near Cooke City and West Yellowstone while all other areas were dry. Winds this morning were blowing 10-20 mph from the WSW and mountain temperatures were in the negative single digits F. In most places valley temperatures were about 10 degrees colder. Winds will be relatively calm today blowing westerly at 10-15 mph, and high temperatures will struggle to approach +10F. Only a trace-1 inch of snow will fall near Cooke City and West Yellowstone while more significant snowfall rolls through Wyoming and Utah. Saturday looks like it will be a relatively nice day in the mountains with light winds, some sunshine and high temperatures near 20F.
The Bridger, Madison and Gallatin Ranges, the Lionhead area near West Yellowstone, the mountains around Cooke City and the Washburn Range:
Avalanche conditions in the backcountry are pretty quiet at the moment. Is this because conditions are somewhat stable or is this because few people were out yesterday? Perhaps it is a little of both. Significant snow fell last weekend and early this week with moderate westerly winds. Since last Friday snowfall totals from SNOTEL sites are:
- Southern mountains: 1.6-3.2 inches of water (about 2-3.5 ft of snow)
- Northern mountains: 1-1.1 inches of water (about 1-1.5 ft of snow)
Receiving this much snow overnight is typically bad for stability. Receiving this much snow over 7 days is much better for overall stability, and avalanche activity was confined to the new snow. No avalanches breaking on deeper layers in the snowpack were reported. Winds have calmed and shouldn’t increase much until later this weekend. Yesterday the Moonlight Basin Ski Patrol reported fairly stiff layers of new snow that were “locked up”.
The snowpack in most places is strong and deep (total depths of 5-8 ft) with few concerns aside from wind slabs that are becoming harder to trigger. A layer of facets that formed in early February exist about 2-3 ft deep in the N. Gallatin Range and on isolated slopes near Lionhead. Fortunately this layer has show significant strengthening. It deserves some consideration as it may be a problem on very isolated slopes like one Doug found on Lionhead (video). Before riding committing lines, dig 2-3 ft deep on a representative slope and assess this layer if it is present. Otherwise, assess bonding within the new snow using a combination of slope cuts, hand pits, and quick stability tests.
For today on slopes steeper than 35 degrees the avalanche danger is rated MODERATE which means small human triggered avalanches are possible in specific areas (i.e. near ridges and under cornices) and large ones are possible in isolated areas. Less steep slopes have a LOW danger and generally safe avalanche conditions.
I 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.
Upcoming Events
3rd Annual Montana Ale Works Fundraiser
Tuesday, March 1 at 6:00 p.m. in the Railcar at Ale Works in Bozeman
Cost: $25 to benefit the Friends of the Avalanche Center
Details: Chef Roth at Montana Ale Works is creating tapas style servings that will be paired with select beer from Lone Peak Brewery. More information HERE.
Pinhead Classic
The 30th Annual Pinhead Classic on is Saturday, March 5th. “Gangsters and Flappers” is this year’s costume theme, so come dressed up to race, socialize and wind great prizes. Registration is $30 but get you all sorts of cool stuff. All proceeds benefit the Friends of the Avalanche Center. Check out the website http://pinheadclassic.com for details.
OTHER NEWS
New Snowpits Page
In response to our survey we added a new page to the website with images of our snowpit profiles. This page is under the Resources/Other Info tab at www.mtavalanche.com/snowpits
Backcountry Skier Survey – Researchers at Alaska Pacific University are studying decision making in backcountry skiers and would like to get information from you. If interested in this 10-15 minute survey, go to this website: https://www.surveymonkey.com/s/SE_AK_Backcountry_Skiing_Research