GNFAC Avalanche Advisory for Thu Jan 3, 2013

Not the Current Forecast

Good morning. This is Mark Staples with the Gallatin National Forest Avalanche Advisory issued on Thursday, January 3 at 7:30 a.m. Today’s advisory is sponsored by Cooke City Motorsports in partnership with the Friends of the Avalanche Center. This advisory does not apply to operating ski areas.

Mountain Weather

Overnight warm air moved into the area, and this morning mountain temperatures were near 20 degrees F. An inversion has put most valley temperatures just below zero F and in West Yellowstone valley temperatures were at -20 degrees F. Yesterday for a brief period winds increased both in the Bridger Range and near Cooke City. By this morning winds were blowing 10-15 mph from the West and North with gusts of 20 mph. Near Bridger Bowl, mid-mountain winds were blowing 20-30 mph. Today mountain temperatures will climb into the high 20s F and low 30s F under clear, sunny skies. Winds should be mostly calm blowing 5-10 mph.

Snowpack and Avalanche Discussion

Bridger Range   Madison Range   Gallatin Range

Lionhead area near West Yellowstone   Cooke City

A low danger does not mean no danger and there is always some avalanche problem to consider. Today the primary problem is a combination of older wind slabs resting on small, faceted crystals.

Cold nights and relatively warm, sunny days formed small, faceted crystals near the snow surface in some places.   In recent days, short periods of increased winds occurred in various areas. In places like the Bridger Range, downslope winds formed slabs far below ridgetops. Avalanches can be triggered where wind slabs rest on these weak facets. Unfortunately knowing exactly where this combination exists is difficult. Doug didn’t find this combination near Cooke City yesterday where he was riding, but not finding it on one slope doesn’t mean it doesn’t exist on another.

The only reported avalanche activity has been several wind slabs near Cooke City about three days ago and a small avalanche on Saddle Peak. Given the high number of skiers and riders in the backcountry, this avalanche activity is minimal but worth noting. With no new snow and a generally strong snowpack, avalanches are unlikely today and the avalanche danger is LOW.

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.

EDUCATION

TONIGHT, January 3, 6:00 p.m., Eric Knoff presents a 1-hour Avalanche Awareness lecture at 406 Brewing Company, Bozeman.

Tuesday, January 8, 7:00 p.m., 1-hour Avalanche Awareness at Big Timber High School.

Wednesday, January 9, 6:30 p.m., 1-hour Avalanche Awareness at REI, Bozeman.

Thursday and Saturday, January 10 and 12, Rescue Clinic. Thursday at 6:00 p.m. at REI, Bozeman and Saturday at 10 a.m. in the field, location TBD. For more info and to register go http://www.rei.com/event/47692/session/64126

Saturday and Sunday, January 12 and 13, Snowmobiler Introduction to Avalanches with Field Course. For more information and to sign up: https://www.ticketriver.com/event/4979-snowmobiler-introduction-to-avalanches-w-field

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