Just before Christmas in 2010, storms rolled in from the Pacific, soaking Los Angeles and then dumping prodigious amounts of precipitation — 69 centimetres in three days — on Mt. Baldy, a ski area in the San Gabriel Mountains, about an hour from downtown L.A.
Some of that precipitation arrived as snow, leaving Baldy a winter wonderland. But would people be able to get there? The deluges had also washed out roads. It took Herculean efforts by county crews to restore access.
This winter, the story at Baldy is exactly the opposite — as it is in much of the West. Tahoe is bone dry. Homewood on Monday reported five of 62 trails were open. Northstar, better armored with snowmaking, had dropped the rope on 27 of 97.
Colorado's big destination resorts were only marginally better. While Aspen boasted of 20 centimetres of powder and a town full of smiles on Sunday, Vail still hadn't opened its Back Bowls, the latest since the eerily similar winter of 1980-81.
But at least Vail is open. Not so at Bogus Basin, the community ski area near Boise, Idaho. For that matter, after getting drenched last year, Mt. Baldy this week was preparing to open the chairlift to the top of the 10,000-foot mountain for scenic rides. Ski season? Maybe later. Not now.
"It is very likely that this has been the driest first week of January in U.S. recorded history," wrote Dr. Jeff Masters, the co-founder of Weather Underground at his blogsite, WunderBlog. Portions of North Dakota and Minnesota had temperatures 9 degrees Fahrenheit above average during December. "The strangely warm and dry start to winter is not limited to the U.S.," he added. "All of continental Europe experienced well above-average temperatures during December."
From tornadoes to heat waves to floods, the last 13 months have been a time of extremes. Can any of this be ascribed to global warming? Climate scientists have typically warned against making too much of individual events. Climate is full of natural variability, they point out, no two years exactly alike. From these individual weather events we get climate, and shifting patterns are most accurately discerned in retrospect.
Kevin Trenberth, of the National Center for Atmospheric Research in Boulder, Colo., describes this explanation as too "wishy-washy." Global warming, he says, is already evident in the extremes. Records are being broken when natural variability, such as El Niña, works in the same direction as human-induced warming.
"Most of the time, the climate and the weather you experience are the same as you experienced before. It's only out here on the tails of the distribution that you are really experiencing something different," he said in Seattle last year at the American Meteorological Society's annual meeting.