Good morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Wednesday, January 19, at 7:30 a.m. Bridger Bowl, in cooperation with the Friends of the Avalanche Center, sponsors today’s advisory. This advisory does not apply to operating ski areas.
Last night’s 6-9 inches around Big Sky and 11 inches at Bridger Bowl fell with barely a whisper of wind. Cooke City picked up an additional five inches with the southern Madison Range getting only 2 inches. Ridgetop winds have been blowing 5-10 mph out of the northwest as temperatures dropped to near 10F. This storm will give us another inch or two before leaving this morning. Clouds will decrease throughout the afternoon and temperatures will rise into the high teens as winds increase out of the west to 15-20 mph.
The mountains around Cooke City and the Washburn Range:
The mountains around Cooke City have gotten 2-3 feet of settled snow since Saturday night (3” SWE). Winds blew out of the west to northwest during most of the storm. Mark and a partner checked on stability yesterday and had to keep their throttles pinned to chew a track through all the new snow. They rode around Lulu and Daisy Passes and only saw a few avalanches that were confined to wind-blown snow in steep, rocky areas (photos). Given the huge load that these mountains were faced with, he was pleasantly surprised at the isolated activity. His snowpits indicated a strong snowpack.
Three inches of snow water equivalency is a lot of weight to support, even for a strong snowpack. These mountains will need a few days without snowfall to fully adjust to the load. Winds on Sunday and Monday heavily drifted snow at all elevations. For today, the avalanche danger is rated CONSIDERABLE on all wind-loaded slopes. Slopes steeper than 35 degrees also have CONSIDERABLE danger while all other terrain has a MODERATE danger.
The Bridger, Madison and Gallatin Ranges including the Lionhead area near West Yellowstone:
Last night’s 6-9 inches from Big Sky to the Bridger Range’s 11 inches fell as 6-7% density powder with winds so calm I had to check the data twice to really believe it. Before this storm, winds blew 20-30 mph out of the west loading many slopes. We are finding that the snowpack, in general, is lacking widespread weak layers and can handle the 12-16” of snow that fell since Saturday night. Our main stability concern is on slopes that got wind-loaded the past few days, and also on terrain that has a thinner, more faceted snowpack. GNF Snow Rangers saw a slide on Cedar Mountain in the northern Madison Range yesterday that broke on a rocky rollover.
My partners and I skied down the west side of the Bridger Range yesterday and found weak, sugary snow on west to southwest aspects where the depth was only a meter deep (video). This mirrored what I saw in Beehive Basin on Sunday (video). In both pits I was unpleasantly surprised at how easily these facets fractured. The Big Sky Ski Patrol triggered a slope on the south face of Lone Peak with explosives that also failed on facets that had gotten weaker (photo). Slopes with underlying facets are isolated and easy to ferret out. If you poke a ski pole to the ground or sink to your crotch when stepping off a sled, you found it. These slopes, as well as slopes with wind loads, are where avalanches can be triggered from. For today, the avalanche danger is rated CONSIDERABLE on all wind-loaded slopes. All other terrain has a MODERATE danger.
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.
SURVEY
The Friends of the Gallatin National Forest Avalanche Center are sponsoring a survey. We’re trying to find out how we're doing, what we can do better and who our users are. The survey is 4 pages long and takes 5-10 minutes to complete. http://www.surveymonkey.com/s/YFCKDZH
Beacon Park Opening Celebration
The Bozeman Recreation Department is celebrating the opening of the Bozeman Beacon Park on Friday, January 28th from 4:00 to 6:00 p.m. at Beall Park, 415 N. Bozeman. The Recreation Department will offer food, refreshments, music, and training on how to use the park with your avalanche beacon. This event is free to the public. For information call 582-2290.
Avalanche Education
January 19, TONIGHT in Bozeman
The Friends of the Avalanche Center will be sponsoring a FREE 1 hr Basic Avalanche Awareness at REI – 6:30 p.m. to 7:30 p.m. Register at www.rei.com/bozeman
January 26, 27 and 29 in Bozeman
Basic Avalanche Awareness – Next Wednesday & Thursday 7:00 p.m. – 9:30 p.m. at MSU EPS Building, Room 103 with a field day on Saturday at Bridger Bowl (more information) (Prepay)
February 2, 3, and 5 in Bozeman
Advanced Avalanche Awareness –Wednesday & Thursday 7:00p.m. – 9:30 p.m. at MSU SUB Room 235 with a field day on Saturday at Bridger Bowl (more information) (Prepay)
For additional information and a listing of other avalanche classes, go to: http://www.mtavalanche.com/workshops/calendar