Current Advisory

GNFAC Avalanche Advisory for Fri Feb 27, 2015

Good morning. This is Mark Staples with the Gallatin National Forest Avalanche Advisory issued on Friday, February 27, at 7:30 a.m. The Community Food Co-op in partnership with the Friends of the Avalanche Center sponsors today’s advisory. This advisory does not apply to operating ski areas.


Mountain Weather: 

Yesterday a few flurries occurred in the mountains near West Yellowstone; otherwise, no snow fell and it was calm and cold. This morning temperatures were in the low single digits F with a few places below zero F. Winds remained surprisingly light this morning blowing westerly at 5-10 mph with gusts of 20 mph in some areas. Today will be mostly cloudy, temperatures should reach the teens F, winds should remain light blowing westerly at 5-10 mph with a few higher gusts, and an inch or two of snow should fall mainly near Big Sky and West Yellowstone.


Snowpack and Avalanche Discussion: 

Northern Gallatin Range

The northern Gallatin Range which includes Hyalite Canyon had most snow lately; 12-20 inches last weekend and about a foot of new snow Tuesday night thru Wednesday. This snow fell on a strong snowpack lacking any persistent weak layers (video), and winds have been unbelievably calm during the last few days. Winds increased a little this morning at the weather station on top of Flanders Mountain blowing 11 mph and gusting 18 mph from the west. The new snow should have bonded well to itself and the underlying snow. The main concern will be fresh wind slabs or drifts. For today the avalanche danger is rated MODERATE on all wind loaded slopes. Avalanches are unlikely on terrain unaffected by the wind where the avalanche danger is LOW.


Bridger Range   Madison Range   Southern Gallatin Range   

Lionhead Area near West Yellowstone   Cooke City

Winds continue to be surprisingly light in the rest of the advisory area. In the Bridger Range near Bridger Bowl, Karl, Eric, and I on three separate field days found good powder, minimal wind, and stable conditions. The only avalanche activity has been very small wind slabs (photo) hardly worth mentioning.

Less snow has fallen further south but enough for isolated wind slabs. Skiers in the southern Madison Range triggered one yesterday about 20 feet wide and 6-10 inches deep running 600 feet on a NNE aspect. They did not see any other avalanche activity. A layer of buried surface hoar exists near West Yellowstone, but it is not an issue with only a few inches of snow falling during the last 2 weeks and no avalanche activity on this layer.

Conditions are generally safe, but avalanches can still happen. Isolated places may have wind slabs like the one triggered yesterday, and odd things can happen as a skier found west of Cooke City on Tuesday when he discovered a natural avalanche (100’ wide, 1000’ vertical, unknown depth) that released on a slope he had skied on Monday. Get out and have fun but don’t let your guard down. For today the avalanche danger is rated LOW.


Eric 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.


  <<   This is the most recent advisory.