GNFAC Avalanche Advisory for Thu Feb 26, 2015

Not the Current Forecast

Good morning. This is Mark Staples with the Gallatin National Forest Avalanche Advisory issued on Thursday, February 26, at 7:30 a.m. A Montana FWP Recreation Trails Grant sponsors today’s advisory. This advisory does not apply to operating ski areas.

Mountain Weather

Since yesterday morning the Bridger Range received another 3 inches of snow, the northern Gallatin Range got 5-10 inches, the Madison Range got 1-2 inches, and the mountains near West Yellowstone and Cooke City remained dry. Temperatures this morning were at 5 degrees F in most areas except Cooke City where it was -2 degrees F, and north easterly winds were remarkably calm blowing 1-5 mph gusting to 10 mph. Today should start cloudy with the sun appearing this afternoon. Temperatures should warm to the teens F and winds will remain calm.

Snowpack and Avalanche Discussion

Northern Gallatin Range

With another 5-10 inches of snow (0.5 inches of SWE) falling in the northern Gallatin Range on top of 3-4 inches the previous day and 12-20 inches last weekend, conditions are pretty good. This snow fell on a snow surface lacking any weak layers as my partner and I found in the northern Gallatin Range on Tuesday (video) where we performed snowmobile-assisted pit digging. Winds were hardly blowing this morning and there are few avalanche concerns. The main issue is that there’s simply a lot of new snow. There may be some isolated wind slabs, avalanches breaking within the new snow, or loose snow sluffs. For today the avalanche danger is rated MODERATE on slopes steeper than 35 degrees and LOW on less steep slopes.

Bridger Range   Madison Range   Southern Gallatin Range   

Lionhead Area near West Yellowstone   Cooke City

Snow falling over the last two days fell on a snow surface lacking any weak layers as Doug found in the northern Bridger Range on Tuesday and my partner and I found on Bridger Peak in the southern part of the range yesterday where our only concerns were small wind slabs that were very easy to avoid (photo). We also experienced dead calm winds yesterday afternoon, a rare treat. Eric skied just north of Bridger Bowl and also found stable conditions.

Less snow has fallen in the last week near Big Sky and Cooke City while the mountains near West Yellowstone haven’t gotten new snow in about 2 weeks. However, a skier just west of Cooke City found a sizable avalanche on a S facing slope on Tuesday (about 100’ wide and 1000’ vertical and unknown depth).This appears to be an isolated event but a good reminder to not let our guard down. The skier commented that there were several lessons “(1) If you can ride it , it can slide, (2) Even in Low [danger] conditions, strange things can happen, (3) human factor - I was up there yesterday very ill-prepared, just out the back door for a quick ski. Wake up call for me.”

Today generally safe avalanche conditions exist and the avalanche danger is rated LOW. A low danger doesn’t mean no danger, just that human triggered avalanches are unlikely.

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.

AVALANCHE EDUCATION and EVENTS

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

1-hour Avalanche Awareness, Bozeman, REI, 6:30 - 8 p.m., Wednesday, March 11.

02 / 25 / 15  <<  
 
this forecast
 
  >>   02 / 27 / 15