Good morning. This is Eric Knoff with the Gallatin National Forest Avalanche Advisory issued on Monday, March 18 at 7:30 a.m. Grizzly Outfitters in partnership with the Friends of the Avalanche Center sponsors today’s advisory. This advisory does not apply to operating ski areas.
Yesterday’s storm totals averaged 4-6 inches in most mountain locations. The Bridger Range was the big winner with a total of 9 new inches. This morning, clear skies have allowed temperatures to drop into the single digits F and winds are blowing 10-20 mph out of the WNW. Today, highs will climb into the upper teens to mid-twenties F under partly to mostly cloudy skies and winds will continue to blow 10-20 from the WNW. A light weather disturbance will move over the area this afternoon producing a chance for mountain snow showers. 1-2 inches is possible by tomorrow morning.
Bridger Range Madison Range Gallatin Range
Lionhead area near West Yellowstone Cooke City
Yesterday, the snow flew and the winds blew. On some slopes, the new snow bonded well to the old snow surface. On others, sensitive soft slabs were easily triggered by local ski patrols conducting avalanche mitigation and by backcountry skiers.
Today, wind slabs will remain the primary avalanche problem. Sustained winds out the west-northwest have formed wind drifts on upper elevation slopes below ridgelines and on cross-loaded sub-ridges.
Wind drifts will be temperamental. Some will be glued on while others will be touchy - making for tricky travel conditions. It’s unlikely that fresh wind slabs will break far and wide, but they will be large enough to carry a skier or rider into unfavorable terrain. Keep an eye out for rippled wind textured snow and rounded wind pillows. Avoiding areas that appear heavily loaded will be the best way to avoid avalanches.
There is a slight chance that a skier or rider could tickle a buried weak layer 2-3 feet deep. Upper elevation slopes, specifically those in steep, rocky terrain will be areas where this scenario is possible.
Today, heightened avalanche conditions exist on wind loaded slopes which have a MODERATE avalanche danger. Non-wind loaded slopes have a LOW avalanche danger.
Doug 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.