GNFAC Avalanche Advisory for Wed Feb 4, 2015

Not the Current Forecast

Good morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Wednesday, February 4, at 7:30 a.m. Mystery Ranch in partnership with the Friends of the Avalanche Center sponsors today’s advisory. This advisory does not apply to operating ski areas.

Mountain Weather

Snowfall yesterday and last night favored the Yellowstone Club with a foot of powder. The northern Madison, Gallatin and Bridger Ranges show 6-8 inches, while only 2-4 inches fell in the south. Winds decreased yesterday afternoon and are currently 5-10 mph out of the west to north. Mountain temperatures are in the mid-teens under mostly cloudy skies.  Today will see some sun but cloud up again tonight with a trace to an inch falling by morning.

Snowpack and Avalanche Discussion

Bridger Range   Madison Range   Gallatin Range   Lionhead area near West Yellowstone   Cooke City

Since Sunday the mountains have about an inch of snow water equivalence which has equated to a foot of snow; a little more around Cooke City and a lot less around West Yellowstone where only 4-6 inches fell.  From Big Sky to West Yellowstone to Cooke City this new snow buried feathers of surface hoar (photo) on some slopes.  “Some” is the word to focus on because there are many slopes with stable snow, yet some are hiding this new weak layer which could be triggered.  Yesterday my partner and I rode our sleds by braille around foggy Lionhead. We dug three pits with mixed results since finding the buried surface hoar was more difficult than I anticipated. On one slope we found two layers of it, one old and one new, and determined triggering an avalanche would be possible (video and photo). During a moment of better visibility we saw a small natural avalanche on a steep rollover in the new snow, which was a heads up that the freshly buried surface hoar is around and unstable. The only way to find it is to dig, but luckily that’s easy since these layers are shallowly buried.

The snowfall only ended hours ago and has not had a chance to stabilize. I anticipate the new snow will be easily triggered on steep terrain: lots of sluffs and small soft slabs. On slopes without the buried surface hoar the snowpack is strong and avalanches will be confined to the new snow. I expect some action today and am rating the avalanche danger CONSIDERABLE on slopes steeper than 35 degrees and MODERATE elsewhere. Be careful not to let your excitement for powder get in the way of good travel habits.

AN ARTICLE FOR PARENTS

Are you a parent of a kid that skis at a ski area? Do you know if they head out-of-bounds into the sidecountry? Doug’s article “Sidecountry”: Rated R sheds light onto the seriousness of skiing the uncontrolled and unpatrolled slopes next to a ski area.

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.

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.

TONIGHT: 1-hour Avalanche Awareness, Bozeman, REI, 6:30 p.m., Wednesday, February 4.

1-hour Avalanche Awareness, Great Falls, Back Alley Pub, Thursday, February 5.

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.

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