AccuWeather official predicts heavy El Niño snows for central Colorado
October 20, 2015
Steve Root, a chief analytics officer and senior vice president of sales at AccuWeather, doesn't like blanket pronouncements about how El Nino guarantees a snowy winter throughout the country.
"It bugs me," he said.
But 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.
AccuWeather is a private-sector weather-services company that provides micro-forecasts covering every ZIP code in the U.S.
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 of a lull in midwinter and then the "opportunity" for a second, prolific peak of snowfall in March and April, he said.
Here are the eye-popping numbers from Root's forecast:
• He forecast snowfall 150 to 170 percent of average in November.
• He foresees December to start good and remain so through the holidays. The snowfall for the month will be 190 to 200 percent of average.
• The El Nino effect will likely "wane" in January and February, Root said, though his definition of "wane" will still make skiers and snowboarders 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 wild card, according to Root. The patterns from past El Nino 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 high Pacific Ocean water temperatures that create the El Nino. The uncertainty of that reaction makes it "risky" to make a late-winter forecast, he said.
"All El Ninos are not the same," Root said. "In fact, I look at El Ninos as a 4-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 Nino 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 Nino 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.
"In my opinion, central Colorado is going to be the target," he said, referring back to the 4-inch fire hose. "That's where this thing is going to start, it's going to take off and expand."
"I think this season is going to be good for almost all the central and southern Colorado resorts," Root later added.
They will have the advantage over resorts to the north and west, in Root's outlook. Ski resorts in the Northeast may get decent snow, but nothing like Colorado, he said.
"There is going to be some wacky things going on this year," Root said. Other destination ski resorts may just have a cloudy and cold winter with little snowfall. That will make them "unattractive" compared with Colorado, he said.
The winters he examined all brought similar weather to the mountains of Colorado. The snowfall in October was below normal, according to Root. The precipitation cranked up in November.
So far this year, the atmosphere has yet to respond to the El Nino.
"I suspect it's going to take some time for the atmosphere to say, 'OK, I see what the ocean is doing; I'm going to slowly react to that,' and once it starts, then it will respond more like a typical El Nino," Root said. "I suspect that will happen sometime in November."
Regarding his forecast for a late-winter peak in March and April, Root repeated his cautionary tale about El Nino acting like a fire hose.
"You never know where it's going to squirt," he said.
So, he advises skiers and snowboarders to make sure they capitalize on the great conditions he foresees evolving in the early season and keep their fingers crossed for another snow surge in March and April.