Good Morning. This is Mark Staples with the Gallatin National Forest Avalanche Advisory issued on Friday, March 23 at 7:30 a.m. Montana Import Group, in partnership with the Friends of the Avalanche Center, sponsors today’s advisory. This advisory does not apply to operating ski areas
At 4 a.m. mountain temperatures were in the mid 30s F, about 10 degrees warmer than yesterday morning. South winds were blowing 10 mph and gusting 15-30 mph. Today will have a mix of sun and clouds and a little precipitation this afternoon. South winds will continue and temperatures will be in the 40s F.
WET SNOW AVALANCHE DANGER
The snow surface warmed quickly yesterday and became very wet but few wet slides were observed. Although last night was relatively warm, the snowpack will be in a sort of holding pattern today with respect to wet snow avalanches. Cloudy skies should limit much more warming of the snow today, and the primary factor affecting wet snow avalanches will be the possibility of rain. Today the wet snow avalanche danger is MODERATE.
The Bridger Range, southern Gallatin Range, entire Madison Range and the Lionhead area near West Yellowstone:
It has only been 3 days since a major avalanche cycle and 4 days since we issued an avalanche warning. Many large and destructive avalanches were observed in the Bridger Range (video), southern Madison Range (video), and the Lionhead (video) and Hebgen Lake areas. Pictures are posted on the photo page. Most of these slides fractured near the ground and some fractured about 3 ft above the ground. Slopes that did not slide are now prime places for human triggered avalanches. Fewer natural avalanches occurred near Big Sky because less snow fell, but this area has the same snowpack structure making human triggered avalanches just as likely.
The weak layers responsible for this avalanche cycle are buried deep in the snowpack; consequently, warm spring weather will have little effect on these layers in the short term. Time and patience are needed. Although the odds of triggering an avalanche decrease a little each day, the consequences remain severe. Today with this in mind, the avalanche danger is rated CONSIDERABLE on slopes steeper than 35 degrees. Less steep slopes have a MODERATE avalanche danger.
The northern Gallatin Range and mountains around Cooke City:
In the northern Gallatin Range and the Cooke City area buried facets exist but are not as widespread as in other areas. Additionally these areas did not receive as much snow from recent storms, thus the snowpack has less stress. Today the avalanche danger is rated MODERATE. However, this season has not been one to be remembered for stable conditions, and I would remain conservative in these areas despite a lower avalanche danger.
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.