Good morning. This is Eric Knoff with the Gallatin National Forest Avalanche Advisory issued on Sunday, February 27, at 7:30 a.m. The On Site Management in cooperation with the Friends of the Avalanche Center, sponsors today’s advisory. This advisory does not apply to operating ski areas.
Overnight a trace of new snow fell in the mountains south of Bozeman. Currently, mountain temperatures are ranging from the single digits above or below zero with Shower Falls Snotel site in the northern Gallatin Range being the warm spot at 13 F. Winds have calmed since yesterday afternoon and are now blowing 10-20 mph out of the W-NW with a few gust reaching into the 30’s. Today, a westerly flow will keep skies partly to mostly cloudy producing a slight chance of mountain snow showers this afternoon. Temperatures will warm into the 20’s and winds will stay out of the west at 10-20 mph. 2-3” of new snow is possible by tomorrow morning.
The Bridger, Madison and Gallatin Ranges, the Lionhead area near West Yellowstone, the mountains around Cooke City and the Washburn Range:
Over the past 24 hours strong west winds have raked the mountains of our advisory area (photo). Although winds have decreased this morning, the damage has been done. Yesterday, I skied north of Bridger Bowl and encountered punchy, grabby and hollow conditions. It was a guessing game as to whether or not slabs would break and move as we skied across them. My partner and I observed recent activity along the ridgelines (photo) and also found cross loading and slabby conditions at mid to lower elevations (video). Slabs were relatively hard and had a magic carpet quality; they could pick you up and take you places you didn't want to go. The Big Sky Ski Patrol also found touchy wind slabs on all aspects of the upper mountain.
Dense wind slabs can be tricky to evaluate. Some will be reactive to the weight of a skier or rider while others will stay put. As these slabs have more time to adjust, they will become increasingly stubborn. This does not mean they should be trusted. Hard slabs have a tendency to fracture once you are on them, making for a potentially unmanageable and dangerous situation. Staying alert and avoiding smooth drifts and large wind rolls will be the best way to avoid triggering a slide. A related problem is the growth of cornices. It’s hard to know when these overhanging beasts have reached their breaking point, but when they do, falling cornices make good triggers for avalanches.
Today:
- Wind loaded slopes steeper than 35 degrees have a CONSIDERABLE avalanche danger.
- Less steep wind loaded slopes have a MODERATE avalanche danger.
- Non-wind loaded slopes steeper than 35 degrees have MODERATE avalanche danger.
- Less steep non-wind loaded slopes have a LOW avalanche danger.
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