Good Morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Valentine’s Day, Tuesday, February 14th at 6:30 a.m. Today’s advisory is sponsored by our sweethearts Allyson, Marcie and Nina who are our biggest supporters. This advisory does not apply to operating ski areas.
At 5 a.m. skies are clear with temperatures in the 20s. Today will be sunny with temperatures reaching the 40s. Winds are blowing W-NW at 15-20 mph and will decrease this afternoon. Sunny skies and above normal temperatures are forecasted the next couple days, so enjoy it.
Wet Avalanches: Above freezing temperatures will increase the wet avalanche danger on slopes getting full sunshine. Rolling pinwheels are a sign the snow surface is losing cohesion and wet-loose avalanches may occur.
Cooke CityIf you Rip Van Winkled the last 2 weeks and missed the action in Cooke City, here’s a recap: it snowed a massive amount (11+ feet in 12 days), the winds blew and slopes avalanched bigger than anyone has seen in 20 years. Here are two videos from Alex’s trip during the storm (one) and Extreme danger (two); and here are two videos (one, two) I made on Sunday after the storm ended. Late Sunday, two snowboarders riding sleds hit a slope on the backside of Daisy Pass and triggered a large avalanche (aerial photo, runout, crown). No one was caught. Many riders are high marking next to huge avalanches, which is risky behavior. Avalanche activity is the #1 sign that adjacent slopes are also dangerous. The snowpack needs time to adjust to this massive load and in the next few days people will still be able to trigger slides. For today, the avalanche danger remains CONSIDERABLE on all slopes.
See our photo page for a thorough tour of the avalanche activity, from the ground and the air (video compilation).
Madison Range Gallatin Range Lionhead area near West YellowstoneThe Madison and Gallatin Ranges and Lionhead area near West Yellowstone have buried layers that came alive over the weekend from last week’s snowfall and wind-loading. Weak snow (facets and/or surface hoar) is buried 1.5-2 feet under the surface which Eric explains in his Beehive Basin video. Skiers and snowmobilers were also able to propagate fractures in their stability tests (photo and video). Additionally, people have seen natural avalanches on wind-loaded slopes north of Big Sky (photo), Hyalite (photo), and Tepee Basin (photo) and human triggered avalanches on Buck Ridge on Saturday and in Sunlight Basin in Taylor Fork on Sunday that resulted in a partial burial (photo of avalanche releasing, photo of rider and airbag). Weak layers that are over burdened with wind slabs can be triggered. Avoiding wind-loaded slopes is the easiest way to stay safe. For today, the avalanche danger is rated CONSIDERABLE on all wind-loaded terrain and MODERATE elsewhere.
Bridger RangeIn the Bridger Range wind-loaded slopes are the biggest threat. On Sunday, skiers triggered a small wind slab below the cliffs of Saddle Peak. In Wolverine Bowl a skier got a poor stability test result (ECTP17) on small-grained facets mid-pack that caused him alarm. This instability is not widespread and not obvious, which means digging and testing is the only way to find it. For today, the avalanche danger is MODERATE on wind-loaded slopes and LOW on all others.
I will issue the next advisory tomorrow morning by 7:30 a.m.
Nearby Incidents
Crazy Mountains: A snowmobiler triggered and was partially buried in a slide on Sunday. More details are forthcoming.
Lincoln, MT: On Friday, a snowmobiler triggered a slide north of Lincoln, MT. He deployed his airbag and was not caught while his sled was partially buried. A short report and photos of the incident here.
NEW! State Snowmobile Trail Map: HERE.
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.
Beacon Training Park at Beall: Open and free to the public for avalanche beacon practice seven days a week from 9 a.m. to 8 p.m., southeast corner of Beall Park in Bozeman.
COOKE CITY
Weekly rescue training and snowpack update, 6:30-7:30 p.m., Cooke City Super 8 on Friday, Lulu Pass Road for field location Saturday (Look for the yellow sign).
ENNIS
February 17, 1-hr Avalanche Awareness, 6-7 p.m., Madison Valley Rural Fire Department Station 1.
Bozeman
February 17-19, Bozeman Split Fest, rescue clinic/avy conditions talk on Friday. More info here.
March 4, Pinhead Classic, Proceeds to benefit Friends of GNFAC. More info here.