From The Aspen Times (Scott Condon) via Glenwood Springs Post Independent:
[Steve] Root has one hell of a winter forecast for Aspen and the mountains of Colorado. It’s not hype, he said, just a look ahead based on evidence from the past…
Root said he sees the winter getting off slowly with lower than usual snowfall this month, but then it will hit with a vengeance. There will be somewhat a lull in mid-winter, then the “opportunity” for a second, prolific peak of snowfall in March and April.
Here are the eye-popping numbers from Root’s forecast:
* He forecasted snowfall 150 to 170 percent of average in November.
* He foresees December to start good and remain good through the holidays. The snowfall for the month will be 190 to 200 percent of average.
* The El Niño effect will likely “wane” in January and February, though Root’s definition of wane will still make skiers and riders smile. He foresees snowfall at 110 to 120 percent of average in January and 110 to 130 percent of average in February. Both months will be cloudy and cold with intermittent snow, he said.
* Late in February comes the wildcard, according to Root. The patterns from past El Niño winters suggest a second peak of prolific snowfall starting in late February and March. There is the potential for snowfall 120 to 160 percent of average, he said.
* He expects winter to hang around well into April with snowfall approaching 200 percent of average.
Root placed a caveat on his end-of-winter forecast, starting in March. He said there is a chance the atmosphere will respond to the warm Pacific Ocean water temperatures that create the El Niño. The uncertainty of that reaction makes it “risky” to make a late winter forecast, he said.
“All El Niños are not the same,” Root said. “In fact, I look at El Niños as a four-inch fire hose. When somebody turns that fire hose on, you don’t really know where that thing is going to spray. It can spray where it did last time or it can spray in a completely different area.”
To try to figure where the hose will spray this winter, he studied the El Niño winters of 1957-58; 1965-66; 1986-87; 1987-88; 1991-92 and 1997-98, the latter being particularly strong. He risk weighted each of those winters based on factors such as whether the El Niño set up the same way and at the same time of year as this year, he said.
He concluded from the patterns in those six winters that the Aspen area will be among the lucky winners, certainly for early winter.