GNFAC Avalanche Forecast for Wed Jan 9, 2013

Not the Current Forecast

Good morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Wednesday, January 9 at 7:30 a.m. Today’s advisory is sponsored by the Yellowstone Club Community Foundation in partnership with the Friends of the Avalanche Center. This advisory does not apply to operating ski areas.

Mountain Weather

In the last 24 hours the southern mountains have picked up 2-4 inches of new snow while the northern mountains received only a trace to an inch. Mountain temperatures are in the mid-twenties with south to southwest winds averaging 20-30 mph and gusts in the 40s. Today will be warm and windy under partly cloudy skies. Tonight clouds will increase and snow showers will drop 2-3 inches of snow down south and a trace to one inch in the northern mountains.

Snowpack and Avalanche Discussion

Madison Range  Southern Gallatin Range  

Lionhead area near West Yellowstone  Cooke City

Since Monday about five inches of snow has fallen around Big Sky, seven inches near West Yellowstone and a foot outside Cooke City. During this time strong winds out of the southwest created deep drifts. In terms of stability, this snow is a game changer because it buried much weaker snow that was at the surface (video). Clear weather last week created small faceted crystals in the top few inches of the snowpack. Some areas (Beehive Basin, Town Hill outside Cooke City) also grew some surface hoar (photo). The type of crystal is not important, but the fact that we buried a layer of very weak snow is. Yesterday, shooting cracks were reported outside Cooke City and the Big Sky Ski Patrol got avalanches to break on wind-loaded slopes that propagated further than they had in the previous weeks. Both of these are signs of increasing instability and red flag warnings that backcountry travel is getting serious.

For today, any slope with a wind-load has a CONSIDERABLE avalanche danger since it’s likely someone can trigger an avalanche. On slopes without a wind-load the avalanche danger is rated MODERATE

Bridger Range   Northern Gallatin Range 

The Bridger and northern Gallatin Ranges have the same weak layer as everywhere else, but they have better stability simply because they have not gotten as much snow. In the Bridger Range yesterday, Mark and his partner toured near Fairy Lake while Eric took a lap on Saddle Peak. They both found that days of strong winds made wildly variable surface conditions. The west side of the range is unscathed, but the east side has ribs of wind scoured sastrugi and wind deposits of dirt scraped from the ridgelines. Mark still found plenty of near surface facets too, but their distribution was random because of the winds. For today the avalanche danger is rated MODERATE on all wind-loaded terrain and LOW on all other slopes.

Tighten It Up

Our days of very good snow stability are on their way out, quite possibly for a long time. Tomorrow’s storm could spike the avalanche danger rapidly and by the weekend natural and human triggered slides could be common. We are bracing ourselves. People have been getting away with murder: multiple skiers and riders on a slope at the same time, not checking the snowpack of their line, uphill tracks crossing starting zones and folks parking in runout zones to name a few. The days of getting away with sloppy backcountry travel are coming to an end. During a Low danger it’s easy to feel smart since there’s no consequence for bad behavior. With more snow it’s going to get serious out there. Take stock and tighten up your scene. The wiggle room for error is bound to get razor thin.

 Mark 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. If you are unsure what types of information we are looking for, this article explains it well (article).

EDUCATION

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

THIS CLASS IS FULL, WAITLIST ONLY. 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. To get on the waitlist:  http://www.rei.com/event/47692/session/64126

Wednesday, January 16, 7:00 p.m. “The Sidecountry is Backcountry” at MSU’s Procrastinator Theater in Bozeman, a free 1-hour presentation.

Saturday, January 19, Rescue Clinic for Snowmobilers in Cooke City starting at Cooke City Motorsports. This 6 hour clinic teaches how to use avalanche rescue gear and perform an avalanche rescue.  Registration is required. For more info and to sign up, visit: https://www.ticketriver.com/event/4980-companion-rescue-clinic-for-snowmobilers

Saturday, January 19, 6 -7 p.m., 1-hour Avalanche Awareness at the Cooke City Community Center.

01 / 8 / 13  <<  
 
this forecast
 
  >>   01 / 10 / 13