GNFAC Avalanche Advisory for Tue Jan 27, 2015

Not the Current Forecast

Good morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Tuesday, January 27, at 7:30 a.m. Today’s advisory is sponsored by Buck Products and Javaman. This advisory does not apply to operating ski areas.

Mountain Weather

Last night did not freeze in the mountains, the second night for many locations. Temperatures this morning are in the high 30s to 40F at 10,000 feet under clear skies. Winds are west to southwest at 15-20 mph with gusts of 35 mph. Today will be near record warmth with mountain temperatures reaching 50F. Skies will start sunny but thin high clouds will filter the brute force of the sun this afternoon. Late tonight a trace to one inch of new snow may fall in the southern mountains.

Snowpack and Avalanche Discussion

Wet Avalanche Danger

It’s sad to write a spring avalanche forecast in January, but here we are. Mountain temperatures hit 50F yesterday producing wet loose avalanches in the gullies up Hyalite, around Cooke City (photo) and a few others near Big Sky and in the Bridger Range. It did not freeze again last night and air temperatures are expected to reach 50F. High cirrus clouds may filter enough sunlight to shield the snow from a large avalanche cycle, but without a solid freeze wet loose avalanches are expected and the wet snow avalanche danger will rise to CONSIDERABLE on all sunny slopes today.

Bridger Range

Other than wet snow instability, the snowpack in the Bridger Range is stable and generally safe. Yesterday’s 50F temperatures bonded wind drifts in place. There are no buried weak layers causing widespread instability, so regular backcountry caution is advised. If a slope has a weakness it will be found in the top 6-12” of the snowpack. There might be an ice crust or lens of small facets but their distribution is very isolated. For today the dry snow avalanche danger is rated LOW on all slopes.

Madison Range  Gallatin Range  Cooke City

Lionhead area near West Yellowstone 

Wet snow avalanche danger is the theme today, but on shaded slopes or deeper in the snowpack, dry snow still exist. The only concern is weak snow found 6-12 inches under the surface; either an ice crust capped with small facets in the northern ranges or buried surface hoar in the southern mountains. These instabilities are patchy and hard to find.  But a few reports from the weekend remind us to be alert: natural slides on wind-loaded slopes in the southern Madison Range on Sunday, a small snowmobiler triggered slide in Lionhead on Friday (photo) and on Sunday a 100+ foot wide avalanche was seen on a southeast facing slope in Hyalite. People are skiing and riding big lines and the snowpack is mostly stable (video). The tropical temperatures will weaken the surface snow and create wet slides in the short term, but help consolidate and strengthen these layers in the long term. For today, the dry snow avalanche danger is rated MODERATE on slopes steeper than 35 degrees that had a previous wind-load and LOW elsewhere.

To dig deeper into the forecast, our “What’s Been Happening” page keeps track of the weather and avalanche activity while our videos clearly explain our concerns.

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.

TONIGHT: Avalanche Forecaster’s Beer Social Fundraiser

We still have tickets for the 5-6:30 p.m. seating!

The Friends of the Avalanche Center and Montana Ale Works are hosting an Avalanche Forecaster’s Beer Social Fundraiser the evening of January 27th. Get more information and buy tickets here: https://www.ticketriver.com/event/14010

AVALANCHE EDUATION and EVENTS

Take a look at our Education Calendar for all our classes being offered.

Advanced Avalanche Workshop with Field Course, MSU Bozeman, evening lectures 7-9:30 p.m. Wednesday and Thursday, January 28 and 29, with an all-day field session on Saturday. Get more information and register here: https://www.ticketriver.com/event/12445

1-hour Avalanche Awareness, Dillon, UM Western, 6:30 p.m., Tuesday, January 27.

1-hour Avalanche Awareness for Snowmobilers, Livingston, 7 p.m., Tuesday, January 27, Yellowstone Ranger District.

1-hour Avalanche Awareness for Snowmobilers, West Yellowstone, 7 p.m., Saturday, January 31, Holiday Inn.

1-hour Avalanche Awareness for Snowmobilers, Lewistown, 9 a.m. and 11:30 a.m., Saturday, January 31, Fergus Country Trade Center. More info here: http://www.mtavalanche.com/images/15/thunderstruck-13-premiere-and-avalanche-classes

01 / 26 / 15  <<  
 
this forecast
 
  >>   01 / 28 / 15