El Niño, a warming event of the eastern equatorial Pacific Ocean that affects weather patterns in the United States and elsewhere, has strengthened in recent months and already appears to have influenced Colorado's fall weather, says Klaus Wolter, an atmospheric scientist with the University of Colorado at Boulder and the National Oceanic and Atmospheric Administration.
Last month's storm brought anywhere from several inches to a few feet of snow along the Front Range while the most recent storm saw up to a foot of snow in some places. It's a scenario that is typical of El Niño during the fall, said Wolter.
"Four of the last five El Niños have had a snowy October here on the Front Range of Colorado," said Wolter. "In general, it tends to be wetter than average in the fall season -- September through November -- from Arizona through New Mexico and Colorado into the high plains."
But according to Wolter, this year's El Niño most likely will impact Colorado's winter weather in a way many skiers won't like.
"In the high country, and this is essentially everything north of Telluride, the ski resorts at the highest elevations tend to be drier with an El Niño winter."
This doesn't mean that ski areas in Colorado won't get snow, said Wolter, but that they'll get fewer midwinter storms because the storm track will be mostly to the south.
"You get fewer storms, and every once in a while we'll get hit and those storms can be healthy storms, by all means, but you shouldn't expect a lot of powder skiing," he said.
But there is a silver lining to this, said Wolter. While chances are that the state will have fewer snowstorms, temperatures will tend to hover closer to normal and there should be fewer windstorms, especially along the Front Range.
"An El Niño doesn't mean you can't get a windstorm, it just means you don't get high wind speeds like 60 miles per hour for days on end," he said.
But as winter comes to a close, Wolter expects the storm track to move back north and that should bring heavier snowstorms to the Front Range and a few areas of the high country if El Niño is still a factor next spring.
"The Front Range and ski resorts just west of the divide -- Winter Park, Keystone, Arapahoe Basin -- all these places have a tendency to have a wet spring " during an El Niño, he said.
If the current El Niño continues to grow into a "strong event," then Southern California, Arizona and New Mexico will have their best chance in years to get a wetter-than-normal winter, he said. And that would be a good thing because Arizona and California continue to suffer from a prolonged drought.
The last El Niño to influence Colorado's winter weather was in 2006-07, Wolter said. But that one produced an unusually snowy midwinter and he said the state should not expect a repeat of the blizzards that hit the Front Range just before Christmas and that lasted through the first weeks of 2007.