Conditions ripe for avalanches
November 30, 2006
When 2 to 3 feet of powder fell this week on top of old, rotten layers of snow from previous storms, it created ideal conditions for avalanches in the mountains surrounding Aspen, according to a local expert.”Right now we have this house of cards building,” said Brian McCall, a founder of the Roaring Fork Avalanche Center. He is concerned about when that house of cards starts to fall.Backcountry adventurers aren’t seeing a lot of natural slides right now, McCall said, and that could be giving them a false sense of security. The snowpack is very vulnerable to skiing, snowmobiling and other human activities triggering slides, he said.The Roaring Fork Avalanche Center started last season, thanks to private donations and in-kind assistance from the U.S. Forest Service. McCall and his colleagues share information about avalanches and avalanche danger throughout the Roaring Fork River drainage. There are daily updates on the center’s website, http://www.rvavalanche.org.The center rated the danger “considerable” in alpine areas and at treeline Thursday. It was rated moderate below treeline with considerable danger on northwest, north and east aspects.”Any slopes steeper than 30 degrees are suspect for avalanche and should be treated with extra caution, or even avoided at this time,” the center’s message said.Small slides were reported both Tuesday and Wednesday along Richmond Ridge, south of Aspen Mountain. There were no reports of injuries, but both victims were partially buried.McCall said conditions are ripe for slides because of the storm pattern this fall. The high country received several large storms in September and October, but they were separated by long dry spells. The snow base weakened and became unstable.Then came this week’s big dump. Two feet of snow fell on the mountains around Aspen, and 35 inches hit Marble, McClure Pass and Schofield Pass.”It’s a pretty significantly load in a short time there,” McCall said.The snowpack from the latest storm won’t really bond with the lower layers for months. And the subzero weather of Wednesday and Thursday created conditions that will make it difficult for future snowfall to bond with the current upper layer, according to McCall.As this week’s snow layer consolidates it will form a “dense slab” that rests on a weaker layer. “Avalanches, although less frequent, could become larger and more destructive,” McCall wrote on the center’s website.The condition of the snowpack couldn’t be more different than conditions last year, according to McCall. There were numerous, frequent storms in the late fall and early winter 2005. The snow that fell in each storm bonded well. It created a solid base for the entire season.”I’m trying to get people to realize this isn’t last year’s snowpack,” McCall said.Avalanche center benefit setThe Roaring Fork Avalanche Center needs private donations to provide its service throughout this winter, and supporters will get a chance to help this month.The Carbondale restaurant Six89 is hosting the RFAC Social and Benefit Dinner on Monday, Dec. 11. Drinks start at 6 p.m., followed by a silent auction and a four-course dinner with wine.The cost is $68.90 per person. Profits benefit the avalanche center.A similar event last spring sold out, so reservations are recommended by calling the restaurant at 963-6890.Backcountry adventurers and other supporters who cannot make the dinner but want to support the avalanche center can go to its website, http://www.rvavalanche.org, for information on where to send a check and look for the line for “make a donation.”Scott Condon’s e-mail address is firstname.lastname@example.org.The Aspen Times, Aspen, Colo.