Current Advisory

GNFAC Avalanche Advisory for Tue Mar 31, 2015

Good morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Tuesday, March 31, at 7:30 a.m. Grizzly Outfitters in partnership with the Friends of the Avalanche Center sponsor today’s advisory. This advisory does not apply to operating ski areas.


Mountain Weather: 

It did not freeze in the mountains last night and temperatures are in the upper 30s to low 40s. Skies are partly cloudy with ridgetop winds from the southwest averaging 10-15 mph with gusts to 25 mph. Today will be warm and mostly sunny with temperatures getting to 50F before a cold front arrives this evening. Ahead of the front, winds will increase and rain will fall before tuning to snow with temperatures dropping into the high teens. By morning I expect 2-3 inches of snow.


Snowpack and Avalanche Discussion: 

Bridger Range   Madison Range   Gallatin Range   Lionhead area near West Yellowstone   Cooke City 

Without freezing temperatures the snowpack is primed to lose its structural integrity as soon as the sun hits the slopes. The surface will wet quickly and water will weaken the snowpack. In the Bridger Range yesterday I took the snowpack’s temperature and found that the coldest area was 10 cm below the surface where it was only reading -2C, i.e. barely freezing (photo). Eric was in Beehive Basin and found similar concerns: a snowpack that will quickly weaken given the round-the-clock above freezing temperatures (video, photo).

My fingers are crossed that clouds will roll in earlier than expected and shield the snow from the sun, but I’m not betting on it. As the snow surface gets wet I expect to see wet loose avalanches by late morning. These may run far and gouge deep into the snow. I am not expecting wet slabs, but skiers in Cooke City saw evidence of wet loose slides originating in rocky terrain that pulled out adjacent small slabs (photo).

Sloppy, mushy snow and pinwheels rolling downhill are signs that the snow surface is prime to avalanche. As warm temperatures and strong solar input soften the snow surface, both natural and human triggered avalanches will become likely. For today the avalanche danger will start out LOW but rapidly rise to CONSIDERABLE.


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.


RECALL OF ORTOVOX S1+ AVALANCHE TRANSCEIVERS

All necessary information about the recall can be found at: www.ortovox.com/recall-s1plus.


The last advisory of the season will be Sunday, April 12.



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