The Jackson Hole News&Guide checks in with the Bridger-Teton Avalanche Center to bring readers weekly snowpack reports and summaries. Find avalanche reports, snow conditions and new features at JHAvalanche.org. Backcountry travel in avalanche terrain is inherently dangerous. This report is not meant to replace your own information gathering, only to be one source, and is not a replacement for taking an avalanche safety course.
Weather: It was a deep week, with 45 inches of snow in Rendezvous Bowl. Grand Targhee Resort and the western slopes of the Tetons didn’t see as much snow, but overall the region had some good powder skiing.
During the storm that ran from Thursday to Sunday, winds were well above 20 mph, with gusts that reached 71 mph Saturday. The wind effect caused the Avalanche Center to raise the danger rating to high for several days and caution that wind slabs could be found on all aspects at all elevations.
Snowpack: The new snow, which brought up to 4 1/2 inches of water at the upper elevations, mostly carried danger of wind slabs. However, the possibility of a slide stepping down to basal weak layers was low because of a relatively deep, stable snowpack.
Avalanche Center Director Bob Comey said he and his team went to Commissary Ridge in the Wyoming Range and found conditions similar to those in the Tetons.
“We found a couple slides that happened during the storm,” he said, “but the snow has gained a bunch of stability.”
As in maritime climates the snowpack is reactive during and directly after a storm, but the danger subsides quickly as the slabs bond to their underlying layers. Twenty backcountry avalanches were reported between Thursday and Saturday, and although they were mostly on leeward north to east aspects, they happened on slopes all around the compass.
Just a few days out from the storm, no avalanches have been reported in recent days, and the danger has dropped to moderate.
Outlook: Storms will continue to roll through the region, though National Weather Service predictions say they will bring little precipitation and lots of wind. Comey said skiers should still be vigilant in noting observations, especially when they see crust formation on sunlit aspects or if the weather clears for a few days and allows for facet formation.
“Right now, we’re just looking at what’s going on with the most recent storm and the snow surfaces before that as each storm comes in,” he said.