GNFAC Avalanche Advisory for Tue Dec 12, 2017

Good Morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Tuesday, December 12^th at 6:45 a.m. Today’s advisory is sponsored by Edward Jones and Bountiful Table. This advisory does not apply to operating ski areas.

Mountain Weather

We are hostages under an oppressive regime of high pressure. There’s no new snow, winds are west at 10-20 mph and an inversion has created above freezing temperatures at the ridgetops and low 20s in the valleys. West Yellowstone and Cooke City have been spared the inversion, but will not escape the warm temperatures which will reach the low 40s everywhere. A slow change back to winter begins on Friday, so don’t despair.

Snowpack and Avalanche Discussion

Bridger Range

Gallatin Range

Madison Range

Lionhead Range

Cooke City

There’s been no new snow, no wind-loading and no recent avalanches. We have no reports of cracking or collapsing and stability tests are benign. The snowpack is generally stable. Buried 1-2’ deep is an ice crust that formed during Thanksgiving that we are using as a visual marker in the snow (photo). Isolated instabilities (i.e. wind slab) would be found above this layer so we recommend digging to the crust and testing the snow, even during a low danger. Yesterday my partner and I skied Divide Peak up Hyalite and did a few stability tests, which did not dissuade us from skiing our line (video, snowpit).

It did not freeze at the ridgetops last night and may not for a couple more days. The mountains around Cooke City and West Yellowstone have below freezing temperatures this morning, but will warm this afternoon. Across our forecast area the snow surface will get moist on sunny slopes and I expect to see pinwheels rolling off steep slopes along with a few small, wet loose avalanches (photo, photo). While seemingly inconsequential, a small wet slide could push a skier off a cliff or into other high consequence terrain.

For today, the avalanche danger is LOW. But as stated above, be wary of wet avalanches on sunny slopes and dig to the ice crust before committing to avalanche terrain.

If you get out and have any avalanche or snowpack observations to share, drop a line via our website, email (mtavalanche@gmail.com), phone (406-587-6984), or Instagram (#gnfacobs).

Upcoming Avalanche Education and Events

Events and Education Calendar

BILLINGS

TONIGHT, Dec. 12, Avalanche Awareness for Snowmobilers, 6-7:30 p.m. at Red Lion Hotel and Convention Center, Billings

BOZEMAN

Dec. 13, Avalanche Awareness, 6:30-8 p.m. at Gallatin Valley Snowmobile Association, 4-Corners

Dec. 21, Avalanche Awareness, 6-7:30 P.m. at Play It Again Sports, Bozeman

Jan. 12 and 13, Companion Rescue Clinic, Info and Register

Jan. 17, 18 and 20 or 21, Introduction to Avalanches w/ Field Day, Info and Register Here

Jan. 24, 25 and 27, Advanced Avalanche Workshop w. Field Day, Info and Register Here

Feb. 9 and 10, Companion Rescue Clinic, Info and Register

WEST YELLOWSTONE

Dec. 14 and 15, Snowmobiler Introduction to Avalanches with Field Course, Info and Register Here

Jan. 6, Avalanche Awareness, 7-8 p.m. at West Yellowstone Holiday Inn Conference Center

COOKE CITY

15 and 16 December, Weekly Current Conditions and Avalanche Rescue, 6:30-7:30 p.m. Friday @ the Super 8, and anytime between 10-2 on Saturday @ Lulu Pass road

The Last Word

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A daily checklist is a great way to help prevent common mistakes or overlooking important data when travelling in the backcountry. This article from Backcountry Magazine discusses how to use and create your own backcountry checklist.