Good Morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Wednesday, March 24, at 7:30 a.m. The Dance Center, in cooperation with the Friends of the Avalanche Center, sponsors today's advisory. This advisory does not apply to operating ski areas.
Yesterday morning a trace to one inch of snow fell at the tail end of the storm. Ridgetop winds were westerly at 15 mph with mountain temperatures reaching the upper 20s. A high pressure ridge is bringing sunny, warm, stable weather today. West to southwest winds will be light at 10-15 mph with temperatures climbing to near 50F. Skies will become partly cloudy late tonight with another chance of snow late Thursday.
WET SNOW AVALANCHE DANGER
Yesterday's afternoon sun turned the snow into mashed potatoes on south aspects. Today's sun and spring temperatures will go a big step further and create wet slides on all but the coolest, most north facing slopes. I expect to see wet point release avalanches near cliffs and rock outcroppings which could trigger avalanches running on deeper layers. The wet snow avalanche danger will increase with the rising sun and quickly become CONSIDERABLE by early afternoon on all sun exposed slopes.
The Bridger, Gallatin and Madison Ranges, the Lionhead area near West Yellowstone, the mountains around Cooke City and the Washburn Range:
A total of seven to ten inches of snow fell in the northern Gallatin and Bridger Ranges by yesterday morning. The Big Sky area had similar amounts at the higher elevations of Lone Peak while the northern Madison and Cooke City areas reported 3-4 inches. This new snow bonded well to the old surface on all slopes except very steep, wind loaded terrain where the Big Sky and Moonlight Basin Ski Patrols were able to release a few isolated drifts.
Yesterday, a skier triggered an avalanche in the Bridger Range south of the ski area on an east facing slope below Argentina Bowl. No one was caught or injured, but the chute broke about 1.5 feet deep on a layer of faceted crystals. We've found this on most slopes in southwest Montana. The strength of this layer varies which is always a bit of a nightmare. Weak layers are easy to manage when they're uniformly unstable, which this is not. An experienced group of snowmobilers in the Gravelly Range on Sunday triggered a two foot deep avalanche on this layer too. It was small, but still completely buried a rider. Lucky his partners were nearby and dug him out quickly (photo1, photo2, photo3).
We're also concerned about the thick layer of large facets at the ground. We haven't had any avalanches breaking on it in a few weeks, but I don't trust it. Between this layer and the upper one that the snowmobiler and skier triggered, I'm on my toes, alert and suspicious. Today, throughout our entire advisory area, the avalanche danger is rated MODERATE on all slopes since human triggered avalanches are still possible.
YOUTUBE: SADDLE PEAK AVALANCHE Q&A
The forum we held March 4th at the Bozeman Public Library on the Saddle Peak Avalanche is now online thanks to the Randy and Kristin Wimberg. The entire 75 minute session can be viewed in two parts. You can find it on our Videos Page or here: Part 1, Part 2.
New Beacon Park
The Friends of the Avalanche Center used a donation from Yellowstone Adventures to purchase an avalanche beacon training park in West Yellowstone. You can search for pre-placed beacons switched on/off by a control panel. Look for it by the orange snow fence just south of the old airport (photo).
Mark will issue the next advisory tomorrow morning at 7:30 a.m. If you get out in the backcountry let us know what you find. You can reach us at 587-6984 or email us at mtavalanche@gmail.com.