There is a 70 percent chance that warm waters in the equatorial Pacific, commonly known as El Niño, will impact the Pacific Northwest during the coming winter, possibly bringing warmer and drier conditions to Oregon.

Forecasters caution, though, that predicting weather more than a week or so out is difficult at best.

Still, the warming of equatorial waters can affect weather across the country and around the globe, making normally cold winters abnormally warm and vice versa. The chances of an El Niño winter can have ramifications for everyone from winter sports enthusiasts to farmers to fishermen.

And it appears an El Niño is more likely than not.

"Forecasters ... favor the onset of El Niño in the coming months," the Climate Prediction Center, part of the National Weather Service, said in its monthly forecast.

What that means locally is a little less certain, according to Laurel McCoy, a meteorologist with the service based in Portland.

"What it means for us is a little wishy-washy," she said. "Going back and looking at the all the Niño winters we've had, statistically, they tend to be warmer than average."

El Niño winter also tend to be drier than average, McCoy said, though precipitation is harder to predict than temperature.

"That doesn't mean that we won't see snow in the Cascades," she continued, though she said the region could see fewer low-elevation snow events.

Though the forecast isn't predetermined by any means, the prospect of a drier than average winter has some climatologists worried.

"Coming off of such a dry, hot summer, our snowpack is depleted," said Kathie Dello, a researcher at Oregon State University and Associate Director of the Oregon Climate Change Research Institute. "We've already spent all our water savings."

According to federal drought monitors, nearly all of Oregon is in at least a moderate drought, with much of the state in either severe or extreme drought.

A drought map of Oregon shows nearly the whole the state in either moderate drought (beige), severe drought (orange) or extreme drought (red).

"We need a decent winter to bring us into next year," Dello said.

-- Kale Williams

kwilliams@oregonian.com

503-294-4048